Semiconductor Devices

Abstract

One embodiment discloses a semiconductor device, including: a semiconductor structure, the semiconductor structure including a first conductive semiconductor layer, a second conductive semiconductor layer and an active layer arranged between the first conductive semiconductor layer and the second conductive semiconductor layer and including a plurality of first recesses and a second recess, the plurality of first recesses being arranged to penetrate the second conductive semiconductor layer and the active layer to a partial area of ​​the first conductive semiconductor layer, the second recess being arranged between the plurality of first recesses; a plurality of first electrodes being arranged in the plurality of first recesses and electrically connected to the first conductive semiconductor layer; a plurality of second electrodes being electrically connected to the second conductive semiconductor layer; and a reflective layer being arranged in the second recess, wherein the sum of the areas of the plurality of first recesses and the areas of the second recesses is 60% or less of the maximum area in a first direction of the semiconductor structure, the areas of the plurality of first recesses and the areas of the second recesses are areas formed on a lower surface of the semiconductor structure, and the first direction is perpendicular to a thickness direction of the semiconductor structure.

Description

Technical Field

[0001] Embodiments relate to semiconductor devices. Background Art

[0002] Semiconductor devices including compounds such as GaN, AlGaN, etc. have many advantages such as wide and easily adjustable band gap energy, etc., and can be variously used as light emitting devices, light receiving devices, various diodes, and the like.

[0003] Specifically, light-emitting devices such as light-emitting diodes or laser diodes using III-V or II-VI compound semiconductor materials can use phosphors or combine colors to achieve various colors such as red light, green light, blue light, ultraviolet light, etc., produced by the development of thin film growth technology and device materials, as well as white light with high efficiency, and have the advantages of low power consumption, semi-permanent life, fast response time, safety and environmental friendliness when compared with traditional light sources such as fluorescent lamps and incandescent lamps.

[0004] In addition, when a light receiving device such as a photodetector or a solar cell is manufactured using a III-V or II-VI compound semiconductor material, due to the development of component materials, the light receiving device absorbs light in various wavelength regions to generate photocurrent, making it possible to use light in various wavelength regions from gamma rays to radio wavelength regions. In addition, taking advantage of the fast response speed, safety, environmental friendliness, and easy control of device materials, the light receiving device can also be easily used in power control, microwave circuits, or communication modules.

[0005] Therefore, the application of semiconductor devices has been extended to transmission modules of optical communication equipment, light emitting diode (LED) backlights replacing cold cathode fluorescent lamps (CCFL) configuring backlights of liquid crystal display (LCD) devices, white LED lighting devices capable of replacing fluorescent lamps or incandescent lamps, headlights of vehicles, traffic lights, sensors for detecting gas or fire, etc. In addition, the application of semiconductor devices can be extended to high-frequency application circuits, other power control devices, and communication modules.

[0006] In particular, a light emitting device emitting light in the ultraviolet wavelength range can be used for curing, medical use, and sterilization by performing curing and sterilization.

[0007] In conventional semiconductor devices, in addition to the upward direction of the active layer, light generated in the active layer can propagate to the side surface of the active layer or in the downward direction. In particular, as the aluminum (Al) component increases, the amount of light emitted to the side surface can be increased. Therefore, there is a problem that the propagation path of light emitted from the semiconductor device becomes longer or the light is absorbed inside the semiconductor structure. Summary of the invention

[0008] Technical issues

[0009] Example embodiments are directed to providing a semiconductor device having improved light extraction efficiency.

[0010] Furthermore, exemplary embodiments are directed to providing a semiconductor device having improved optical power and reduced operating voltage.

[0011] Technical Solutions

[0012] One aspect of the present invention provides a semiconductor device, which includes: a semiconductor structure having a first conductive semiconductor layer, a second conductive semiconductor layer, an active layer arranged between the first conductive semiconductor layer and the second conductive semiconductor layer, a plurality of first recesses, and a second recess, the plurality of first recesses being arranged to pass through the second conductive semiconductor layer and the active layer to a certain area of ​​the first conductive semiconductor layer, and the second recess being arranged between the plurality of first recesses; a plurality of first electrodes, the plurality of first electrodes being arranged in the plurality of first recesses and being electrically connected to the first conductive semiconductor layer; a plurality of second electrodes, the plurality of second electrodes being electrically connected to the second conductive semiconductor layer; and a reflective layer, the reflective layer being arranged in the second recess, wherein the sum of the areas of the plurality of first recesses and the areas of the second recesses may be within a range of 60% or less relative to the maximum area of ​​the semiconductor structure in a first direction, and the areas of the plurality of first recesses and the areas of the second recesses may be areas formed on a lower surface of the semiconductor structure, and the first direction may be a direction perpendicular to a thickness direction of the semiconductor structure.

[0013] A distance between the plurality of second electrodes may be in the range of 3 μm to 60 μm.

[0014] The width of the reflective layer may be in the range of 3 μm to 30 μm.

[0015] A distance between the plurality of second electrodes may be equal to a width of the reflective layer.

[0016] An area in which the plurality of first electrodes are electrically connected to the first conductive semiconductor layer may be in the range of 6.0% to 11.0% with respect to a maximum area of ​​the semiconductor structure in the first direction.

[0017] An area in which the plurality of second electrodes are electrically connected to the second conductive semiconductor layer may be in the range of 40% to 60% with respect to a maximum area of ​​the semiconductor structure in the first direction.

[0018] A ratio of an area in which the plurality of first electrodes are electrically connected to the first conductive semiconductor layer to an area in which the plurality of second electrodes are electrically connected to the second conductive semiconductor layer may be in the range of 1:4 to 1:10.

[0019] The semiconductor structure may include a plurality of first regions separated by the second recess, and the plurality of first electrodes may be arranged in the plurality of first regions.

[0020] An area of ​​the first region may be 2.0 to 5.0 times that of the first electrode.

[0021] An area of ​​the plurality of first regions may be 2.0 to 5.0 times an area of ​​the plurality of first recesses.

[0022] The reflective layer may include an extending portion extending from the second concave portion and configured to contact the second electrode.

[0023] The reflective layer may include a capping layer configured to cover the reflective layer and the second electrode.

[0024] The reflective layer may include a second electrode pad electrically connected to the cladding layer.

[0025] The semiconductor device may further include a low reflection layer electrically connected to the plurality of first electrodes.

[0026] The semiconductor device may further include a substrate electrically connected to the low reflection layer.

[0027] The semiconductor structure can generate light in the ultraviolet wavelength range.

[0028] The first conductive semiconductor layer may include a first layer and a second layer, the first layer being disposed adjacent to the active layer, the second layer being disposed on the first layer, the second layer may have an aluminum composition higher than that of the first layer, and the first electrode may be disposed on the first layer.

[0029] Another aspect of the present invention provides a semiconductor device, which includes: a semiconductor structure, which has a first conductive semiconductor layer, a second conductive semiconductor layer, an active layer arranged between the first conductive semiconductor layer and the second conductive semiconductor layer, a plurality of first recesses, and a second recess, wherein the plurality of first recesses are arranged to pass through the second conductive semiconductor layer and the active layer to a certain area of ​​the first conductive semiconductor layer, and the second recess is arranged between the plurality of first recesses; a plurality of first electrodes, which are arranged in the plurality of first recesses and electrically connected to the first conductive semiconductor layer; a plurality of second electrodes, which are electrically connected to the second conductive semiconductor layer; and a reflective layer, which is arranged in the second recess, wherein the semiconductor structure may include a plurality of first areas separated by the second recesses, and the area ratio of the first recesses to the first areas may be in the range of 1:4 to 1:8.

[0030] The plurality of second electrodes may include a plurality of sub-electrodes arranged in the first region.

[0031] The semiconductor structure may include a second region disposed between a lateral surface of the semiconductor structure and the second recess.

[0032] A separation distance between the side surface of the semiconductor structure and the second recess may be in the range of 1.0 μm to 10 μm.

[0033] The plurality of second electrodes may include an edge electrode disposed in the second region.

[0034] Beneficial Effects

[0035] According to exemplary embodiments, light extraction efficiency can be improved.

[0036] Furthermore, according to exemplary embodiments, optical power can be improved.

[0037] Furthermore, according to the exemplary embodiments, the operating voltage can be improved.

[0038] Various advantageous features and effects of the present invention are not limited to the detailed description and should be easily understood through the description of the detailed embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a cross-sectional view illustrating a semiconductor device according to an embodiment.

[0040] Figure 2 is a conceptual diagram illustrating a process in which light is reflected upward by a reflective layer.

[0041] Figure 3 yes Figure 1 An enlarged view of part A of FIG.

[0042] Figure 4 is a diagram for describing the height difference between the first recessed portion and the second recessed portion.

[0043] Figure 5 is a plan view of a semiconductor device according to an embodiment of the present invention.

[0044] Figure 6 is a diagram illustrating the distribution of current density of a semiconductor device.

[0045] Figure 7a is a diagram illustrating the first area.

[0046] Figure 7b is a diagram for describing the distance between the first areas.

[0047] Figure 8 It is a diagram illustrating the area of ​​the p-ohmic electrode.

[0048] Fig. 9is a photograph of a semiconductor device according to a first embodiment of the present invention.

[0049] Fig.10 is a photograph of a semiconductor device according to a second embodiment of the present invention.

[0050] Fig.11 is a photograph of a semiconductor device according to a third embodiment of the present invention.

[0051] Fig.12 is a graph showing the optical power of the semiconductor device according to the first to third embodiments.

[0052] Fig.13 is a graph showing operating voltages of the semiconductor devices according to the first to third embodiments.

[0053] Fig.14 is a diagram illustrating a semiconductor device according to a fourth embodiment of the present invention.

[0054] Fig.15 is a diagram illustrating a semiconductor device according to a fifth embodiment of the present invention.

[0055] Fig.16 is a diagram illustrating a semiconductor device according to a sixth embodiment of the present invention.

[0056] Fig.17 is a diagram illustrating a semiconductor device according to a seventh embodiment of the present invention.

[0057] Fig.18 is a diagram illustrating a semiconductor device according to an eighth embodiment of the present invention.

[0058] Fig.19 is a graph showing the optical power of the semiconductor devices according to the fourth to eighth embodiments.

[0059] Fig. 20 is a graph showing operating voltages of semiconductor devices according to fourth to eighth embodiments.

[0060] Fig.21 is a scanning electron microscope (SEM) photograph showing a cross section of an eighth embodiment of the present invention.

[0061] Fig. 22 is a plan view of a semiconductor device according to a ninth embodiment of the present invention.

[0062] Fig.23 yes Fig. 22 An enlarged view of portion C of FIG.

[0063] Fig.24 is a photograph of the light emitting structure with power applied.

[0064] Fig.25 is a plan view of a semiconductor device according to a tenth embodiment of the present invention.

[0065] Fig.26a and 26b is a diagram illustrating a semiconductor device according to an eleventh embodiment of the present invention.

[0066] Fig. 27 is a diagram illustrating a semiconductor device according to a twelfth embodiment of the present invention.

[0067] Fig.28 is a diagram illustrating a semiconductor device according to a thirteenth embodiment of the present invention.

[0068] Fig.29 is a conceptual diagram of a semiconductor device package according to an embodiment of the present invention.

[0069] Fig.30 is a plan view of a semiconductor device package according to an embodiment of the present invention.

[0070] Fig.31 yes Fig.30 A modified embodiment of . DETAILED DESCRIPTION

[0071] The exemplary embodiments may be modified in other forms, or various embodiments may be combined with each other, and the scope of the present invention is not limited to each embodiment described below.

[0072] Although an item described in a specific embodiment is not described in the other embodiment, the item can be understood as being related to another embodiment unless otherwise described in the other embodiment or as long as there is no contradictory description therein.

[0073] For example, when features for configuration A are described in a particular embodiment and features for configuration B are described in other embodiments, even when an embodiment in which configuration A and configuration B are combined is not explicitly described, it should be understood that the combined embodiment will fall within the scope of the present invention unless otherwise specified in the other embodiments or as long as there is no contradictory interpretation therein.

[0074] In the description of the embodiments, when an element is described as being formed “on” or “under” another element, the term “on” or “under” includes the meaning that the two elements are in direct (direct) contact with each other and the meaning that one or more other elements are arranged and formed between the two elements (indirectly). In addition, when an element is described as being formed “on” or “under” another element, the description may include the meaning that the other element is formed in the upward direction of the element and formed in the downward direction of the element.

[0075] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which are suitable for implementation by those skilled in the art to which the present invention pertains.

[0076] Figure 1 is a cross-sectional view of a semiconductor device according to an embodiment of the present invention, Figure 2 is a conceptual diagram illustrating a process in which light is reflected upward by a reflection layer, Figure 3 is Figure 1 an enlarged view of part A of Figure 4 and is a diagram for describing the height difference between the first recess and the second recess.

[0077] Referring to Figure 1 , the semiconductor device according to the present embodiment includes a semiconductor structure 120 having a first conductive semiconductor layer 122, a second conductive semiconductor layer 126, and an active layer 124, a first electrode 142 electrically connected to the first conductive semiconductor layer 122, a second electrode 146 electrically connected to the second conductive semiconductor layer 126, and a reflection layer 135 disposed in the second recess 127.

[0078] The semiconductor structure 120 according to the present embodiment can output light in the ultraviolet (UV) wavelength range. For example, the semiconductor structure 120 can emit light in the near-ultraviolet wavelength range (UV-A), light in the far-ultraviolet wavelength range (UV-B), or light in the deep-ultraviolet wavelength range (UV-C). The UV wavelength range can be determined by the aluminum (Al) composition ratio of the semiconductor structure 120.

[0079] For example, UV-A light in the near-UV wavelength range can have a wavelength in the range of 320 nm to 420 nm, UV-B light in the far-UV wavelength range can have a wavelength in the range of 280 nm to 320 nm, and UV-C light in the deep-UV wavelength range can have a wavelength in the range of 100 nm to 280 nm.

[0080] When the semiconductor structure 120 emits light in the UV wavelength range, each semiconductor layer of the semiconductor structure 120 can include a material of Inx1Aly1Ga1-x1-y1N containing Al (0 ≤ x1 ≤ 1, 0 < y1 ≤ 1, and 0 ≤ x1 + y1 ≤ 1). Here, the Al composition can be represented by the ratio of the total atomic weight including the atomic weights of In, Ga, and Al to the atomic weight of Al. For example, when the Al composition is 40%, the 60% Ga composition can be represented as Al40Ga60N.

[0081] In addition, in the description of this embodiment, the meaning of low or high composition can be understood as the difference (percentage (%) point) of composition % between semiconductor layers. For example, when the Al composition of the first semiconductor layer is 30% and the Al composition of the second semiconductor layer is 60%, it can be expressed that the Al composition of the second semiconductor layer is 30% higher than the Al composition of the first semiconductor layer.

[0082] The semiconductor structure 120 includes a plurality of first recesses 128 formed to a certain region of the first conductive semiconductor layer 122 by passing through the second conductive semiconductor layer 126 and the active layer 124 , and at least one second recess 127 disposed between the plurality of first recesses 128 .

[0083] The first insulating layer 131 may be formed on the first and second recesses 128 and 127. The first insulating layer 131 may electrically insulate the reflective layer 135 from the active layer 124 and the first conductive semiconductor layer 122. The first insulating layer 131 may extend from the first and second recesses 128 and 127 to the second conductive semiconductor layer 126.

[0084] The first electrode 142 and the second electrode 146 may be ohmic electrodes. Each of the first electrode 142 and the second electrode 146 may be formed of at least one of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), indium gallium tin oxide (IGTO), aluminum zinc oxide (AZO), antimony tin oxide (ATO), gallium zinc oxide (GZO), IZO nitride (IZON), Al-Ga ZnO (AGZO), IGZO, ZnO, IrOx, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au, Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, Ru, Mg, Zn, Pt, Au, and Hf, but the present invention is not limited to these materials.

[0085] The reflective layer 135 may be disposed in the second concave portion 127. Specifically, the reflective layer 135 may be disposed on the first insulating layer 131 in the second concave portion 127.

[0086] The reflective layer 135 may be formed of a material having a high reflectivity in the UV wavelength range. The reflective layer 135 may include a conductive material. For example, the reflective layer 135 may include Al. When the thickness of the Al reflective layer 135 is in the range of about 30 nm to 100 nm, light in the UV wavelength range may be reflected by 80% or more. Therefore, it is possible to prevent the light emitted from the active layer 124 from being absorbed by the semiconductor layer.

[0087] refer to Figure 2When the Al composition of the semiconductor structure 120 increases, the current distribution characteristics in the semiconductor structure 120 may deteriorate. In addition, compared with GaN-based blue light-emitting devices, the active layer 124 increases the amount of light emitted to its side surface (transverse magnetic (TM) mode). This TM mode may occur in UV semiconductor devices.

[0088] According to the present embodiment, a portion of the region where the current density is low is etched to form the reflective layer 135 so that the light L1 can be reflected upward by the reflective layer 135. Therefore, light absorption in the semiconductor structure 120 can be reduced and light extraction efficiency can be improved. In addition, the directivity of the semiconductor device can be adjusted.

[0089] The first conductive semiconductor layer 122 may be formed of a III-V group or a II-VI group compound semiconductor, and may be doped with a first dopant. The first conductive semiconductor layer 122 may be formed of a semiconductor material having a composition formula of Inx1Aly1Ga1-x1-y1N (0≤x1≤1, 0≤y1≤1, and 0≤x1+y1≤1), and may be selected from, for example, AlGaN, AlN, InAlGaN, and the like. In addition, the first dopant may be an n-type dopant, such as Si, Ge, Sn, Se, or Te. When the first dopant is an n-type dopant, the first conductive semiconductor layer 122 doped with the first dopant may be an n-type semiconductor layer.

[0090] The first conductive semiconductor layer 122 may have a first layer 122a having a relatively low Al composition and a second layer 122b having a relatively high Al composition. The second layer 122b may have an Al composition in the range of 60% to 70%, and the first layer 122a may have an Al composition in the range of 40% to 50%. The first layer 122a may be arranged adjacent to the active layer 124. The Al composition of the first layer 122a may be higher than that of the well layer. In this case, the first layer 122a may solve the problem of light generated in the active layer 124 being absorbed. For example, the first layer 122a may have an Al composition in the range of 5% to 10% higher than that of the well layer, but the present invention is not necessarily limited thereto.

[0091] The first electrode 142 may be arranged on the first layer 122a to ensure relatively smooth current injection characteristics. That is, the first recess 128 may be preferably formed to the region of the first layer 122a. This is because the second layer 122b has a high Al composition, so that the current distribution characteristics of the second layer 122b are relatively low.

[0092] The active layer 124 is a layer where electrons (or holes) injected through the first conductive semiconductor layer 122 meet holes (or electrons) injected through the second conductive semiconductor layer 126. Due to the recombination of electrons and holes, the active layer 124 may be transformed into a low energy level and emit light having a wavelength corresponding to the transformation.

[0093] The active layer 124 may have any one of a single well structure, a multi-well structure, a single quantum well structure, a multi-quantum well (MQW) structure in which well layers and barrier layers are alternately arranged, a quantum dot structure, and a quantum wire structure, but the structure of the active layer 124 is not limited thereto. Both the well layer and the barrier layer of the active layer 124 may include Al.

[0094] The second conductive semiconductor layer 126 may be formed on the active layer 124, may be formed of a III-V group or II-VI group compound semiconductor, and may be doped with a second dopant. The second conductive semiconductor layer 126 may be formed of a semiconductor material having a composition formula of Inx5Aly2Ga1-x5-y2N (0≤x5≤1, 0≤y2≤1, and 0≤x5+y2≤1) or a material selected from AlInN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, or Ba, the second conductive semiconductor layer 126 doped with the second dopant may be a p-type semiconductor layer.

[0095] When the second conductive semiconductor layer 126 is made of AlGaN, hole injection may not be smooth due to low conductivity. Therefore, GaN having relatively high conductivity may be disposed at the lower surface of the second conductive semiconductor layer 126 .

[0096] The thickness d2 of the first electrode 142 may be thinner than the thickness d3 of the first insulating layer 131, and the separation distance d4 between the first electrode 142 and the first insulating layer 131 may be set in the range of 1 μm to 4 μm. The thickness d2 of the first electrode 142 may be 40% to 80% relative to the thickness d3 of the first insulating layer 131.

[0097] When the thickness d2 of the first electrode 142 is 40% to 80% relative to the thickness d3 of the first insulating layer 131, it is possible to solve problems such as delamination and cracks caused by degradation of step coverage characteristics occurring when the lower electrode layer 165 is arranged. In addition, a separation distance d4 between the first electrode 142 and the first insulating layer 131 is set so that the gap filling characteristics of the second insulating layer 132 can be improved.

[0098] refer to Figure 3, the reflective layer 135 may cover one side surface of the second electrode 146 and a portion of the lower surface of the second electrode 146. With this configuration, light incident between the first insulating layer 131 and the second electrode 146 may be reflected upward. However, the reflective layer 135 such as Al may have relatively poor step coverage, and leakage current may be generated due to the migration characteristics of the reflective layer 135, so that reliability may be reduced. Therefore, it may not be preferred that the reflective layer 135 completely covers the second electrode 146.

[0099] The second electrode 146 may be disposed on the lower surface 121 of the semiconductor structure. The thickness of the second electrode 146 may be 80% or less relative to the thickness of the first insulating layer 131. Therefore, when the reflective layer 135 and the cladding layer 150 are disposed, problems such as cracks or delamination of the reflective layer 135 or the cladding layer 150 due to degradation of step coverage can be solved.

[0100] The distance S1 between the plurality of second electrodes may be in the range of 3 μm and 60 μm. When the distance S1 between the plurality of second electrodes is less than 3 μm, the width of the second concave portion 127 becomes narrow, making it difficult to form the reflective layer 135 inside the second concave portion 127. In addition, if the distance exceeds 60 μm, the area of ​​the second electrode 146 is reduced, so that the operating voltage may increase and the optical power may decrease due to the problem of removing the effective light emitting area.

[0101] The width S2 of the reflective layer may be in the range of 3 μm to 30 μm. When the width S2 of the reflective layer is less than 3 μm, it is difficult to form the reflective layer in the second concave portion 127. However, when the width S2 exceeds 30 μm, the area of ​​the second electrode 146 is reduced, so that the operating voltage increases. Therefore, the distance S1 between the plurality of second electrodes may be equal to the width S2 of the reflective layer.

[0102] The width S2 of the reflective layer 135 may be equal to the width of the second recess 127. Each of the width of the first recess and the width of the second recess 127 may be a maximum width formed on the lower surface 121 of the semiconductor structure.

[0103] The reflective layer 135 may include an extension portion 135 a extending from the second concave portion 127 toward the second electrode 146 . The extension portion 135 a may electrically connect the second electrode 146 separated by the second concave portion 127 .

[0104] The width S5 of the extension 135a may be in the range of 0 μm to 20 μm. When the width S5 is greater than 20 μm, the second electrode 146 is completely covered so that the step coverage characteristic may be deteriorated. The width S4 of the reflective layer including the extension 135a may be in the range of 20 μm to 60 μm.

[0105] The first separation distance S3 between the second electrode 146 and the first insulating layer 131 may be set in the range of 0 μm to 4 μm. When the first separation distance is longer than 4 μm, the region where the second electrode 146 is arranged becomes narrower, so that the operating voltage may increase.

[0106] The reflective layer 135 may be disposed within a first separation distance S3 between the second electrode 146 and the first insulating layer 131, and may be in contact with the side and upper surfaces of the first insulating layer 131 and the upper and side surfaces of the second electrode 146 within the first separation distance S3. In addition, a region in which the reflective layer 135 makes Schottky contact with the second conductive semiconductor layer 126 may be disposed within the first separation distance S3 to form a Schottky junction so that current can be easily distributed.

[0107] An angle θ4 between the inclined portion of the reflective layer 135 and the lower surface of the second conductive semiconductor layer 126 may be in the range of 90 to 145 degrees. When the inclined angle θ4 is less than 90 degrees, it is difficult to etch the second conductive semiconductor layer 126, whereas when the inclined angle θ4 is greater than 145 degrees, the etching area of ​​the active layer becomes larger, so that the light emitting efficiency is degraded.

[0108] The cladding layer 150 may cover the reflective layer 135 and the second electrode 146. Therefore, the second electrode pad 166, the cladding layer 150, the reflective layer 135 and the second electrode 146 may form one electrical path.

[0109] The cladding layer 150 may completely surround the reflective layer 135 and the second electrode 146, and may be in contact with the side surface and the upper surface of the first insulating layer 131. The cladding layer 150 may be formed of a material having high adhesive strength to the first insulating layer 131, formed of at least one material selected from the group consisting of Cr, Al, Ti, Ni, Au, etc., and alloys thereof, and formed of a single layer or a plurality of layers.

[0110] When the cladding layer 150 contacts the side and upper surfaces of the first insulating layer 131, thermal and electrical reliability of the reflective layer 135 and the second electrode 146 may be improved. In addition, the cladding layer 150 may have a function of reflecting light emitted between the first insulating layer 131 and the second electrode 146 upward.

[0111] The cladding layer 150 may be disposed within a second separation distance between the first insulating layer 131 and the second electrode 146. The cladding layer 150 may be in contact with the side surface and the upper surface of the second electrode 146 and the side surface and the upper surface of the first insulating layer 131 within the second separation distance. In addition, a region in which the cladding layer 150 makes Schottky contact with the second conductive semiconductor layer 126 may be disposed within the second separation distance to form a Schottky junction so that current can be easily distributed.

[0112] Return to reference Figure 1 , the lower electrode layer 165 and the bonding layer 160 may be arranged along the topography of the lower surface of the semiconductor structure 120 and the first recess 128 and the second recess 127. The lower electrode layer 165 may be formed of a material having a high reflectivity. For example, the lower electrode layer 165 may include Al. When the lower electrode layer 165 includes Al, the lower electrode layer 165 serves to reflect light emitted from the active layer 124 toward the substrate 170 upward, thereby improving light extraction efficiency.

[0113] The second insulating layer 132 electrically insulates the reflective layer 135, the second electrode 146, and the cladding layer 150 from the lower electrode layer 165. The lower electrode layer 165 may be electrically connected to the first electrode 142 by passing through the second insulating layer 132.

[0114] The thickness of the first insulating layer 131 may be in the range of 40% to 80% relative to the thickness of the second insulating layer 132. When the range of 40% to 80% is satisfied, the thickness of the first insulating layer 131 becomes thinner and the upper surface of the reflective layer 135 becomes closer to the first conductive semiconductor layer 122, so that light extraction efficiency can be improved.

[0115] For example, the thickness of the first insulating layer 131 may be to When the thickness of the first insulating layer 131 is less than When the thickness of the first insulating layer 131 is thicker than The reflective layer 135 and the cladding layer 150 are disposed on the upper portion and the side surface of the first insulating layer 131, and the step coverage characteristics of the reflective layer 135 or the cladding layer 150 are not good, so that delamination or cracks may be caused. When delamination or cracks are caused, problems such as reduced electrical reliability or reduced light extraction efficiency may occur.

[0116] The thickness of the second insulating layer 132 can be to When the thickness of the second insulating layer 132 is less than When the thickness of the second insulating layer 132 is thicker than When the device is formed of a plurality of insulating layers 131 and 132, the reliability may be degraded due to the pressure or thermal stress applied to the device during the process, and the process time may be extended, so that the unit cost of the device increases. The thickness of the first insulating layer 131 and the second insulating layer 132 is not limited thereto.

[0117] The bonding layer 160 may include a conductive material. For example, the bonding layer 160 may include a material selected from the group consisting of Au, Sn, In, Al, Si, Ag, Ni, and copper (Cu) or an alloy thereof.

[0118] The substrate 170 may be formed of a conductive material. For example, the substrate 170 may include a metal or a semiconductor material. The substrate 170 may be a metal having high electrical conductivity and / or high thermal conductivity. In this case, the heat generated during the operation of the semiconductor device may be quickly dissipated to the outside.

[0119] The substrate 170 may include a material selected from the group consisting of Si, molybdenum (Mo), tungsten (W), Cu, and Al, or alloys thereof.

[0120] The second electrode pad 166 may be made of a conductive material. The second electrode pad 166 may have a single layer or multilayer structure and may include Ti, Ni, Ag, and Au. For example, the second electrode pad 166 may have a structure of Ti / Ni / Ti / Ni / Ti / Au.

[0121] The central portion of the second electrode pad 166 is pressed down so that the upper surface of the second electrode pad 166 may have a concave portion and a convex portion. A wire (not shown) may be bonded to the concave portion of the upper surface. Therefore, the bonding area may be widened so that the second electrode pad 166 and the wire may be more firmly bonded.

[0122] The second electrode pad 166 may serve to reflect light, so that when the second electrode pad 166 is disposed close to the semiconductor structure 120 , light extraction efficiency may be improved.

[0123] The distance between the second electrode pad 166 and the semiconductor structure 120 may be in the range of 5 μm to 30 μm. When the distance is less than 10 μm, it is difficult to ensure a process margin, whereas when the distance is greater than 30 μm, the area in which the second electrode pad 166 is arranged becomes larger in the total area of ​​the semiconductor device, so that the area of ​​the light emitting layer 124 may be reduced and the amount of light may be reduced.

[0124] The height of the protrusion of the second electrode pad 166 may be higher than that of the active layer 124. Therefore, the second electrode pad 166 may reflect light emitted upward from the active layer 124 in the horizontal direction of the semiconductor device, so that light extraction efficiency may be improved and light directivity may be controlled.

[0125] Irregularities may be formed on the upper surface of the semiconductor structure. The irregularities may improve the extraction efficiency of light emitted from the semiconductor structure 120. The average height of the irregularities may be different depending on the UV wavelength. In the case of UV-C light, when the height of the irregularities is in the range of 300nm to 800nm ​​and the average height thereof is in the range of 500nm to 600nm, the light extraction efficiency may be improved.

[0126] The passivation layer 180 may be disposed on the upper surface and the side surface of the semiconductor structure 120. The thickness of the passivation layer 180 may be to When the thickness is less than When the thickness is greater than 100 mm, the passivation layer 180 may not be sufficient to protect the semiconductor device from external moisture or foreign substances, and thus may deteriorate the electrical and optical reliability of the semiconductor device. When the optical circuit is distorted, stress applied to the semiconductor device may become greater to deteriorate optical reliability, or process time may be prolonged to increase unit cost.

[0127] refer to Figure 4 , a protrusion height H1 of the second recess 127 may be higher than a protrusion height H2 of the first recess 128. Here, the protrusion height may be defined as a vertical distance from the active layer 124 to upper surfaces of the first and second recesses 128 and 127.

[0128] Specifically, the protrusion height H1 of the second recess 127 may satisfy the following relational expression 1.

[0129] [Relational expression 1]

[0130] H1=W4×tan(θ1)

[0131] Here, W4 is a distance from a middle point C1 between the first and second recesses 128 and 127 adjacent to each other to an upper surface C2 of the second recess, and θ1 is in the range of 0.5 degrees to 5.0 degrees.

[0132] When θ1 is less than 0.5 degrees, the height of the reflective layer becomes relatively low, making it difficult for the reflective layer to perform an effective reflective function. In addition, when θ1 exceeds 5.0 degrees, the height of the reflective layer becomes too high, so that there is a problem that the area of ​​the active layer is excessively reduced in proportion to the height of the reflective layer. In addition, there is a problem that the recess process and the insulation process should be managed more accurately.

[0133] For example, the distance from the middle point C1 of the second concave portion to the upper surface C2 may be in the range of 20 μm to 40 μm, and θ1 may be 2.3 degrees. The protrusion height of the second concave portion 127 may be in the range of about 300 nm to 800 nm. In this case, the light emitted from the active layer 124 in the TM mode may be effectively reflected upward.

[0134] The second recess 127 may be formed to be higher than the first recess 128. However, the present invention is not particularly limited thereto, and the height of the first recess 128 may be equal to the height of the second recess 127.

[0135] The inclination angle θ2 of the first concave portion 128 may be in the range of 40 to 70 degrees or 60 to 70 degrees, and the inclination angle θ3 of the second concave portion 127 may be in the range of 40 to 70 degrees or 60 to 70 degrees.

[0136] Figure 5 is a plan view of a semiconductor device according to an embodiment of the present invention, Figure 6 is a diagram illustrating the distribution of current density of a semiconductor device, Figure 7a is a diagram illustrating the first region, Figure 7b is a graph for describing the distance between the first regions, and Figure 8 It is a diagram illustrating the area of ​​the p-ohmic electrode.

[0137] refer to Figure 5 , the semiconductor device 100 may include a plurality of first regions 136, each of which is separated by a reflective layer 135 or a second concave portion in a plan view. The first concave portion 128, the second concave portion, the reflective layer 135, and the first region 136 may be regions formed on the lower surface of the semiconductor structure. The plurality of first regions 136 may be independent spaces separated by predetermined intervals. In addition, the plurality of first regions 136 may be light emitting regions.

[0138] The first region 136 may have various shapes. For example, the first region 136 may have a polygonal shape such as a hexagonal, octagonal, or triangular shape, or a circular shape.

[0139] Each of the plurality of first electrodes 142 and the plurality of first recesses 128 may be arranged in the first region 136. According to this structure, the reflective layer 135 may surround the first electrode 142 in which current is distributed. Therefore, light emitted near the first electrode 142 may be reflected upward by the reflective layer 135 surrounding the first region 136.

[0140] The reflective layer 135 may be arranged in a region where regions each having a current density of 40% or less relative to 100% of the current density of the first electrode 142 are connected. For example, a distance between a center of a first concave portion and a center of a second concave portion arranged on a horizontal line of the first concave portion may be in a range of 5 μm and 40 μm.

[0141] When the distance is less than 5 μm, the active layer in the region with high current distribution may be etched to deteriorate the luminous efficiency, however when the distance is longer than 40 μm, the region with poor current distribution characteristics remains so that the light extraction efficiency may be reduced. When the reflective layer is formed in the region with a current density less than 30%, the light emitting region may become excessively wider, so that the light extraction efficiency may be deteriorated. In addition, a considerable portion of the light emitted to the side surface is likely to be absorbed by the semiconductor structure.

[0142] refer to Figure 6 , when the Al component increases, the current distribution effect may be reduced. Therefore, the current is distributed only near the first electrode 142, so that the current density can be sharply reduced at a position far from the first electrode 142. Therefore, the effective light emitting area P2 becomes narrower.

[0143] The effective light emitting region P2 may be defined as a boundary position at which the current density is in the range of 30% to 40% relative to the position P1 near the first electrode at which the current density is highest. For example, a distance in the range of 5 μm to 40 μm from the center of the first recess 128 may be defined as the boundary position. However, the boundary position may vary depending on the Al composition and the level of the injection current.

[0144] The current density in the low current density region P3 between the first electrodes 142 is low, so that the low current density region P3 hardly contributes to light emission. Therefore, according to the present embodiment, a reflective layer is formed in the low current density region, so that light extraction efficiency can be improved.

[0145] However, it is inefficient to form a reflective layer over the entire area of ​​the low current density region P3. Therefore, it may be advantageous to increase optical power by leaving only an area where a reflective layer is to be formed and arranging the first electrodes densely, possibly in the remaining area.

[0146] refer to Figure 7a , the reflective layer 135 may include an inclined portion 135b and an upper portion 135c. Most of the light emitted from the active layer 124 may be reflected upward by the inclined portion 135b.

[0147] The first region 136 defined by the reflective layer 135 may have an area 2.0 to 5.0 times that of the first electrode 142. In this case, the reflective layer 135 may be formed in a region where a current density is 40% or less relative to that of the first electrode 142. Alternatively, the first region 136 defined by the reflective layer 135 may have an area 2.0 to 5.0 times that of the first recess 128. The area of ​​the first region 136 may be adjusted according to the Al concentration of the semiconductor structure 120.

[0148] refer to Figure 7b The interval T1 between adjacent first recesses may be the sum of the distance T2 from the center of the first recess to the second electrode and the distance S1 between the second electrodes. As described above, the distance S1 between the second electrodes needs to be ensured to be at least 3 μm or more.

[0149] The sum of the areas of the plurality of first recesses 128 may be in the range of 12% to 24% relative to the maximum horizontal area of ​​the semiconductor structure. When the sum of the areas of the plurality of first recesses is greater than 24%, the interval T1 between the first recesses becomes narrower. Therefore, the distance S1 between the second electrodes may not be ensured. When the sum of the areas of the plurality of first recesses is less than 12%, the area of ​​the n-type electrode becomes small, making it difficult to obtain sufficient current distribution.

[0150] For example, when the sum of the areas of the plurality of first recesses is 12%, the interval T1 between the first recesses may be 130 μm, and the distance T2 from the center of the first recess to the second electrode may be 63.5 μm. Thus, an interval of about 3 μm may be ensured to form the reflective layer.

[0151] In addition, when the sum of the areas of the plurality of first recesses is 24%, the interval T1 between the first recesses may be 101 μm, and the distance T2 from the center of the first recess to the second electrode may be 49 μm. Therefore, an interval of about 3 μm may be ensured to form the reflective layer of the first recess.

[0152] refer to Figure 8 , as the number of the first recesses increases or the distance S1 between the second electrodes becomes wider, the areas of the plurality of second electrodes 146 decrease.

[0153] The semiconductor structure 120 may include a plurality of first regions 136 separated by the second recess 127 and a second region 137 defined between a side surface E1 of the semiconductor structure 120 and the second recess 127. A spacing distance S1 between the first regions 136 may be equal to or wider than a width of the second recess 127.

[0154] The plurality of second electrodes 146 may include a plurality of sub-electrodes 147 arranged within the first region 136 and an edge electrode 148 arranged within the second region 137 .

[0155] A plurality of sub-electrodes 147 may be disposed between the first recess and the second recess. The plurality of sub-electrodes 147 are separated from each other, but may be electrically connected to each other through the reflective layer.

[0156] The edge electrode 148 may be continuously arranged along the edge of the semiconductor structure 120. However, the present invention is not particularly limited thereto, and the edge electrode 148 may be divided into a plurality of edge electrodes. Alternatively, the edge electrode 148 may be omitted.

[0157] The separation distance d1 between the second recess 127 and the side surface E1 of the semiconductor structure 120 may be in the range of 1.0 μm to 10 μm. When the separation distance d1 is shorter than 1.0 μm, it is difficult to ensure the process margin. In addition, when the separation distance d1 is longer than 10 μm, the area involved in light emission is reduced, so that the light extraction efficiency may be deteriorated. However, the present invention is not particularly limited thereto, and the second recess 127 and the reflective layer may be formed to the side surface E1 of the semiconductor structure 120. In this case, the edge electrode 148 may be divided into a plurality of edge electrodes.

[0158] Fig. 9 is a photograph of a semiconductor device according to a first embodiment of the present invention, Fig.10 is a photograph of a semiconductor device according to a second embodiment of the present invention, Fig.11 is a photograph of a semiconductor device according to a third embodiment of the present invention, Fig.12 is a graph showing the optical power of the semiconductor device according to the first to third embodiments, and Fig.13 is a graph showing operating voltages of the semiconductor devices according to the first to third embodiments.

[0159] refer to Fig. 9 , when the first concave portion is 14, it can be confirmed that only the periphery of the first electrode emits light, and the remaining portion hardly emits light. Fig.10 When the number of the first concave portions increases to 31, it can be seen that the light emitting area becomes larger than Fig. 9 The luminous area is wider. In addition, see Fig.11 , can confirm with Fig.10 That is, as the area of ​​the first electrode increases, the current distribution characteristics are improved so that most of the active layer is involved in light emission.

[0160] refer to Fig.12 , it can be confirmed that the optical power of the second embodiment in which the number of the first recesses 128 is 31 is increased to 114.7% relative to the 100% optical power of the first embodiment in which the number of the first recesses 128 is 14. When the number of holes is 44, it can be confirmed that the optical power is increased to 140.1%. That is, it can be seen that the total area of ​​the active layer is reduced, but the area of ​​the active layer involved in light emission is increased.

[0161] refer to Fig.13 , it can be confirmed that the operating voltage in which the number of the first recesses 128 is 31 is reduced to 87% relative to the 100% operating voltage of the first embodiment in which the number of the first recesses 128 is 14. In addition, when the number of the holes is 44, it can be confirmed that the operating voltage is further reduced to 78%. That is, it can be confirmed that the total area of ​​the first electrode is increased and the current distribution characteristics are improved, so that the operating voltage is reduced.

[0162] Fig.14 is a diagram illustrating a semiconductor device according to a fourth embodiment of the present invention, Fig.15 is a diagram illustrating a semiconductor device according to a fifth embodiment of the present invention, Fig.16 is a diagram illustrating a semiconductor device according to a sixth embodiment of the present invention, Fig.17 is a diagram illustrating a semiconductor device according to a seventh embodiment of the present invention, Fig.18 is a diagram illustrating a semiconductor device according to an eighth embodiment of the present invention, Fig.19 is a graph showing optical power of semiconductor devices according to fourth to eighth embodiments, and Fig. 20 is a graph showing operating voltages of semiconductor devices according to fourth to eighth embodiments.

[0163] Table 1 below shows the active layer region, the p-ohmic electrode region (second region), the recess region, the n-ohmic electrode region (first region), and the number of first recesses of the fourth to eighth embodiments.

[0164] The active layer area may be a mesa etched area of ​​the semiconductor structure and may be an area ratio of the active layer to the maximum horizontal area of ​​the semiconductor structure, wherein by adding the mesa etched area to the recessed area, the area of ​​the semiconductor structure may be the maximum cross-sectional area in the horizontal direction.

[0165] The p-electrode area is an area ratio of the second electrode to the maximum area of ​​the semiconductor structure in the horizontal direction.

[0166] The n-electrode area is an area ratio of the first electrode to the maximum area of ​​the semiconductor structure in the horizontal direction.

[0167] The fourth and seventh embodiments were tested by forming a reflective layer, and the fifth, sixth, and eighth embodiments were tested without forming a reflective layer.

[0168] [Table 1]

[0169]

[0170] refer to Figures 14 to 18 From Table 1, it can be seen that as the number of first concave portions increases, the effective light emitting areas P2 overlap. Therefore, the total active layer area is reduced, but most of the active layers may be involved in light emission.

[0171] The first area where the plurality of first electrodes 142 contact the first conductive semiconductor layer 122 may be in a range of 6.0% to 11% relative to the maximum cross-sectional area of ​​the semiconductor structure 120 in the horizontal direction. The first area may be the sum of the areas where the plurality of first electrodes 142 contact the first conductive semiconductor layer 122.

[0172] When the first area of ​​the plurality of first electrodes 142 is less than 6.0%, the current distribution characteristics are insufficient to reduce the optical power, however, when the first area of ​​the plurality of first electrodes 142 exceeds 11%, the interval between the second electrodes is excessively reduced, making it difficult to ensure a space where a reflective layer will be formed. In this case, in order to form a first area in the range of 6.0% to 11%, the area of ​​the plurality of first recesses may be in the range of 12% to 24% relative to the maximum area of ​​the semiconductor structure in the horizontal direction.

[0173] As a result of the test, the fourth to seventh embodiments secure a space between the second electrodes in which the reflective layer is to be formed, but the eighth embodiment does not secure a space in which the reflective layer including the extension portion is to be formed.

[0174] The second region where the second electrode 246 contacts the second conductive semiconductor layer 126 may be in the range of 40% to 60% of the maximum cross-sectional area in the horizontal direction of the semiconductor structure 120. The second region may be the total area where the second electrode 246 contacts the second conductive semiconductor layer 126.

[0175] When the second area is less than 40%, the area of ​​the second electrode becomes too small, thereby causing problems of increased operating voltage and reduced hole injection efficiency. When the second area exceeds 60%, the first area cannot be effectively widened, thereby causing problems of reduced electron injection efficiency.

[0176] The second area may be equal to or smaller than the remaining area except for the area of ​​the plurality of first recesses and the plurality of second recesses formed on the lower surface of the semiconductor structure. Therefore, the third area, which is the sum of the areas of the plurality of first recesses and the plurality of second recesses, may be 60% or less relative to the maximum area of ​​the semiconductor structure in the horizontal direction.

[0177] When the third region is 60% or more relative to the maximum area of ​​the semiconductor structure in the horizontal direction, the area of ​​the second electrode becomes too small, making it difficult to form a reflective layer. In addition, there are problems of increased operating voltage and reduced hole injection efficiency.

[0178] The area of ​​the plurality of second recesses may be in the range of 4.8% to 5.7% relative to the maximum area of ​​the semiconductor structure in the horizontal direction. When the area of ​​the plurality of second recesses is less than 4.8%, it is difficult to form a reflective layer, but when the area of ​​the plurality of second recesses is greater than 5.7%, the second region becomes smaller, causing the operating voltage to rise.

[0179] The first area and the second area have an inverse relationship. That is, when the number of the first recesses is increased so as to increase the number of the first electrodes, the area of ​​the second electrode is reduced. In order to increase the optical power, the distribution characteristics of electrons and holes should be balanced. In addition, in order to form a reflective layer, it is important to appropriately determine the ratio of the first area to the second area.

[0180] The area ratio of the first region where the plurality of first electrodes contact the first conductive semiconductor layer to the second region where the plurality of second electrodes contact the second conductive semiconductor layer (first region: second region) can be preferably controlled to be 1:4 or greater. When the area ratio is less than 1:4, it is difficult to ensure a space where a reflective layer will be formed, as in the eighth embodiment.

[0181] In addition, when the area ratio is greater than 1:10, the first region becomes relatively small, as in the first and second embodiments, so that the current distribution characteristics may be deteriorated. For example, in the case of the first embodiment, it is confirmed that the first region is only about 1.8%, making the current injection efficiency significantly poor. Therefore, light is emitted only from the area near the first electrode.

[0182] According to an exemplary embodiment, an area ratio of the first recess 128 to the first region 136 may be in a range of 1:4 to 1:8. When the area ratio is less than 1:4, the number of the first recesses 128 increases, making it difficult to ensure a space where the reflective layer 135 will be formed. In addition, when the area ratio is greater than 1:8, the area of ​​the n-electrode becomes relatively small, so that the current distribution characteristics may be deteriorated.

[0183] In the fourth embodiment, the area ratio of the first recessed portion 128 to the first region 136 is 1:8, and in the seventh embodiment, the area ratio of the first recessed portion 128 to the first region 136 is 1:4. In this case, since the radius of the first recessed portions is the same, it can be seen that as the number of the first recessed portions increases, the area of ​​the first region gradually becomes narrower. Here, the area of ​​the first region 136 is the total area including the first recessed portions.

[0184] refer to Fig.19 , it can be confirmed that the optical power of the fifth embodiment in which the number of first recesses is 62 is reduced relative to the 100% optical power of the fourth embodiment in which the number of first recesses is 48. That is, it can be confirmed that the light extraction efficiency is improved by the reflective layer as in the fourth embodiment.

[0185] Similarly, in the seventh embodiment in which the number of first recesses is 81 and a reflective layer is formed, it can be seen that the optical power is higher than that of the eighth embodiment in which the number of first recesses is 96 without forming a reflective layer.

[0186] refer to Fig. 20, even when the number of first recesses increases from 48 to 96, the operating voltage does not change significantly.

[0187] refer to Fig.21 In the case of the eighth embodiment, when the width S2 of the reflective layer 135 is about 4.5 μm, it can be confirmed that cracks occur at the reflective layer 135. Therefore, when the width of the second concave portion is narrowed to about 4.5 μm or less, it can be confirmed that it is difficult to form the reflective layer.

[0188] However, when the tilt angle is adjusted to be smaller, the width of the reflective layer may be controlled to be about 3.0 μm. Therefore, it is preferable that the width S2 of the reflective layer is formed to be wider than about 3.0 μm.

[0189] Fig. 22 is a plan view of a semiconductor device according to a ninth embodiment of the present invention, Fig.23 yes Fig. 22 is an enlarged view of part C of Fig.24 is a photograph of the light emitting structure with power applied.

[0190] Referring to 22 and 23, the first concave portions 128 may extend in a first direction (X direction) and may be arranged and spaced in a second direction (Z direction). Here, the first direction may be a direction perpendicular to the thickness direction (Y direction) of the light emitting structure 120. Hereinafter, the width (area) of each of the first concave portion 128 and the second concave portion 127 is defined as an area formed at a lower portion of the light emitting structure 120.

[0191] The first electrode 142 may be disposed within the first recess 128. The area of ​​the first electrode 142 may be controlled by adjusting the number of the first recesses 128 or adjusting the length of the first recesses 128 extending in the first direction.

[0192] Because current distribution is not relatively easy in a UV light emitting structure with a high Al concentration, the area of ​​the first electrode needs to be wider than that of a GaN light emitting structure emitting blue light. In this embodiment, a plurality of first electrodes 142 contact the first conductive semiconductor layer in the first direction so that the current injection area can become wider.

[0193] In this case, when the first recess 128 is excessively formed to widen the area of ​​the first electrode 142 , the areas of the active layer 124 and the second electrode 146 are reduced, so that it is important to maintain an appropriate area ratio.

[0194] The width W1 of the first concave portion 128 may be in the range of 30 μm to 60 μm. When the width W1 of the first concave portion 128 is less than 30 μm, it is difficult to ensure a process margin for forming the first electrode 142 inside the first concave portion 128, whereas when the width W1 is greater than 60 μm, the active layer is excessively reduced so that the optical power may be reduced.

[0195] The distance d6 between the first concave portions 128 may be in the range of 20 μm and 60 μm. When the distance d6 is less than 20 μm, the active layer is excessively reduced so that the optical power may be reduced, whereas when the distance d6 is greater than 60 μm, the number of the first concave portions 128 is reduced so that it is difficult to fully ensure the area of ​​the first electrode 142.

[0196] The area of ​​the plurality of first electrodes 142 may be in the range of 19% to 29% relative to 100% of the maximum area of ​​the light emitting structure 120 in the first direction. When the area of ​​the plurality of first electrodes 142 is less than 19%, sufficient current injection and diffusion may be difficult, whereas when the area of ​​the plurality of first electrodes 142 is greater than 29%, the area in which the active layer 124 and the second electrode 146 will be arranged is reduced, resulting in problems of reduced optical power and increased operating voltage.

[0197] The area of ​​the plurality of first recesses 128 may be in the range of 30% to 45% relative to 100% of the maximum area of ​​the light emitting structure 120 in the first direction. When the area of ​​the plurality of first recesses 128 is less than 30%, there is a problem of a reduction in the area of ​​the first electrode 142, whereas when the area of ​​the plurality of first recesses 128 is greater than 45%, the area in which the active layer 124 and the second electrode 146 are to be arranged is reduced, so that there are problems of reduced optical power and increased operating voltage.

[0198] The plurality of second recesses 127 may extend in the first direction (X direction), and may be arranged and spaced apart in the second direction (Y direction). The second recesses 127 may be arranged between the plurality of first recesses 128.

[0199] The reflective layer 135 may be disposed within the second concave portion 127. Therefore, the reflective layer 135 may be disposed on both sides of each of the plurality of first electrodes 142 to upwardly reflect light emitted near the first electrode 142. A width S2 of the reflective layer 135 may be equal to or wider than a width of the second concave portion 127.

[0200] As the Al composition becomes higher, the current distribution effect may be reduced. Therefore, the current is distributed only near the first electrode 142, so that the current density may be sharply reduced at a position far from the first electrode 142. Therefore, the effective light emitting area P2 becomes narrower.

[0201] The effective light emitting region P2 may be defined as a boundary position at which the current density is in the range of 30% to 40% relative to the center of the first electrode 142 where the current density is 100%. For example, a distance in the range of 5 μm to 40 μm separated from the center of the first recess 128 in the second direction may be defined as the boundary position. However, the boundary position may vary depending on the level of the injection current and the Al concentration.

[0202] The reflective layer 135 may be disposed at a boundary position where the current density is in the range of 30% to 40%. That is, according to the present embodiment, the reflective layer 135 is formed in a low current density region, so that light extraction efficiency can be improved.

[0203] The length of the second recess 127 in the first direction may be formed longer than the length of the adjacent first recess 128 in the first direction. When the length of the second recess 127 is equal to or less than the length of the adjacent first recess 128, light emitted from the end position of the first recess 128 cannot be controlled.

[0204] Here, the first recess 128 adjacent to the second recess 127 may be two first recesses 128 arranged closest to the second recess 127 in the second direction (Z direction). That is, the second recess 127 may be formed to be longer than at least one of the two first recesses 128 arranged adjacent to the second recess 127 in the left and right sides.

[0205] One end of the second recess 127 may be arranged to be longer (d5) than one end of the first recess 128. The length of the second recess 127 in the first direction may be 104% or more relative to the length of one of the first recesses 128 adjacently arranged in the first direction. In this case, light emitted near both ends of the first electrode 142 may be effectively reflected upward.

[0206] The separation distance d1 between the second recess 127 and the side surface of the light emitting structure 120 may be in the range of 1.0 μm to 10 μm. When the separation distance d1 is less than 1.0 μm, it is difficult to ensure the process margin, and thus it is difficult to arrange the cladding layer 150 to surround the reflective layer 135, so that the reliability may be reduced. In addition, when the separation distance d1 is longer than 10 μm, the area involved in light emission is reduced, so that the light extraction efficiency may be deteriorated. However, the present invention is not particularly limited thereto, and the second recess 127 and the reflective layer 135 may be formed up to the side surface of the light emitting structure 120.

[0207] The area of ​​the plurality of second recesses 127 may be in the range of 4% to 10% relative to 100% of the maximum area of ​​the light emitting structure 120 in the first direction. When the area of ​​the plurality of second recesses 127 is less than 4%, it is difficult to form the reflective layer 135 inside the second recesses 127. In addition, when the area of ​​the plurality of second recesses 127 is greater than 10%, the area of ​​the active layer is reduced, so that the optical power can be reduced.

[0208] The area of ​​the reflective layer 135 may be in the range of 46% to 70% relative to 100% of the maximum area of ​​the light emitting structure 120 in the first direction. The area of ​​the reflective layer 135 that actually reflects light may be equal to or smaller than the area of ​​the second concave portion 127. Here, the area of ​​the reflective layer 135 is an area including an extension portion extending to the lower surface of the light emitting structure 120 to cover the second electrode 146.

[0209] The area of ​​the second electrode 146 may be in the range of 57% to 86% relative to 100% of the maximum area of ​​the light emitting structure 120 in the first direction. When the area of ​​the second electrode 146 is less than 57%, the operating voltage may rise, but when the area of ​​the second electrode 146 is greater than 86%, the area of ​​the first electrode 142 decreases, so that the efficiency and distribution of current injection may be reduced.

[0210] The area of ​​the second electrode 146 may be a remaining area except for the areas of the first and second recesses 128 and 127 in the light emitting structure 120. Therefore, the second electrode 146 may be a fully connected single electrode.

[0211] Fig.25 is a plan view of a semiconductor device according to a tenth embodiment of the present invention, Fig.26a and 26b is a diagram illustrating a semiconductor device according to an eleventh embodiment of the present invention, Fig. 27 is a diagram illustrating a semiconductor device according to a twelfth embodiment of the present invention, and Fig.28 is a diagram illustrating a semiconductor device according to a thirteenth embodiment of the present invention.

[0212] refer to Fig.25 , the semiconductor device may include a side reflective portion 135b connected to both ends of each of the plurality of reflective layers 135. That is, the third recess 129 may be formed at the edge of the light emitting structure 120, and the side reflective portion 135b may be formed inside the third recess 129. The reflective layer 135 and the side reflective portion 135b may include the same reflective material. For example, the reflective layer 135 and the side reflective portion 135b may contain Al.

[0213] The plurality of reflective layers 135 and the side reflective parts 135 b may be electrically connected or may be spaced apart from each other.

[0214] When the plurality of reflective layers 135 and the side reflective parts 135b are connected to each other, a plurality of first regions 136 may be formed. The plurality of first regions 136 may be spaces separated from each other by the plurality of reflective layers 135.

[0215] The first recess 128 and the first electrode 142 may be arranged in each of the plurality of first regions 136. According to the above configuration, light emitted near both ends of the first electrode 142 may be effectively reflected upward.

[0216] The second electrode 146 may be separated into a plurality of second electrodes by the second concave portion 127 and the third concave portion. The plurality of separated second electrodes 146 may be electrically connected to each other by the extension portion of the reflective layer 135.

[0217] Referring to 26a, the reflective layer 135 may not be disposed at the edge of the light emitting device. That is, due to various reasons such as process margin, the reflective layer 135 or the first electrode 142 may be disposed at the edge.

[0218] refer to Figure 26b , the cladding layer 150, the lower electrode layer 165, and the substrate 70 protrude from the edge portion Z1 of the semiconductor device to reflect upward the light L2 emitted from the active layer 124. That is, the side reflection portion may be formed on the edge portion Z1 of the semiconductor device. Therefore, light emitted from the outermost periphery without forming a separate reflection layer may be reflected upward.

[0219] An angle θ4 between the cladding layer 150 and the lower surface of the second conductive semiconductor layer 126 may be in the range of 90 to 145 degrees. When the angle is less than 90 degrees or greater than 145 degrees, the efficiency of upwardly reflecting light traveling toward the side surface may be reduced.

[0220] According to the above configuration, light emitted between the plurality of first concave portions 128 may be reflected upward by the reflective layer 135 , and light emitted from the edge of the light emitting structure 120 may be reflected upward by the cladding layer 150 .

[0221] refer to Fig. 27 , the plurality of reflective layers 135 may extend in the second direction (Z direction), and may be arranged and spaced apart in the first direction (X direction). The arrangement of the first recess 128 and the second recess 127 may be appropriately modified according to the position of the electrode pad or the like.

[0222] refer to Fig.28 The first recess 128 and the first electrode 142 may extend in the first direction and the second direction, respectively. Therefore, a plurality of second regions 137 may be formed in regions provided by intersections of the first recess 128 and the first electrode 142 .

[0223] A plurality of reflective layers 135 may be arranged in the plurality of second regions 137 to reflect light upward. The side reflective portion 135b may be arranged on the edge of the light emitting structure 120. The plurality of reflective layers 135 and the side reflective portion 135b may be electrically connected to each other through the second electrode. However, the present invention is not limited thereto, and the plurality of reflective layers 135 and the side reflective portion 135b may be electrically insulated from each other.

[0224] Fig.29 is a conceptual diagram of a semiconductor device package according to an embodiment of the present invention, Fig.30 is a plan view of a semiconductor device package according to an embodiment of the present invention, and Fig.31 yes Fig.30 A modified embodiment of .

[0225] refer to Fig.29 , the semiconductor device package may include a body 2 in which a recess 3 is formed, a semiconductor device 1 disposed at the body 2, and a pair of lead frames 5a and 5b disposed on the body 2 and electrically connected to the semiconductor device 1. The semiconductor device 1 may include all of the above configurations.

[0226] The body 2 may include a material or coating that reflects UV light. The body 2 may be formed by stacking a plurality of layers 2a, 2b, 2c, 2d, and 2e. The plurality of layers 2a, 2b, 2c, 2d, and 2e may be formed of the same material or different materials.

[0227] The recess 3 is formed to be wider as being farther from the semiconductor device, and a step 3 a may be formed on the inclined surface.

[0228] The light-transmitting layer 4 may cover the recess 3. The light-transmitting layer 4 may be made of a glass material, but the present invention is not particularly limited thereto. The material of the light-transmitting layer 4 is not particularly limited as long as the material can effectively allow light to be transmitted. The inside of the recess 3 may be an empty space.

[0229] refer to Fig.30 , the semiconductor device 10 may be arranged on the first lead frame 5a, and may be connected to the second lead frame 5b through a wire. In this case, the second lead frame 5b may be arranged to surround the side surface of the first lead frame.

[0230] refer to Fig.31 , a plurality of semiconductor devices 10a, 10b, 10c, and 10d may be arranged at the semiconductor device package. In this case, the lead frame may include first to fifth lead frames 5a, 5b, 5c, 5d, and 5e.

[0231] The first semiconductor device 10a may be arranged on the first lead frame 5a and may be connected to the second lead frame 5b by a wire. The second semiconductor device 10b may be arranged on the second lead frame 5b and may be connected to the third lead frame 5c by a wire. The third semiconductor device 10c may be arranged on the third lead frame 5c and may be connected to the fourth lead frame 5d by a wire. The fourth semiconductor device 10d may be arranged on the fourth lead frame 5d and may be connected to the fifth lead frame 5e by a wire.

[0232] The semiconductor device can be applied to various types of light source devices. For example, the light source device can be a concept including a sterilization device, a curing device, a lighting device, a display device, a car light, etc. That is, the semiconductor device can be applied to various electronic devices arranged at a housing and configured to provide light.

[0233] The sterilization device may include a semiconductor device according to an exemplary embodiment to sterilize a desired area. The sterilization device may be applied to household appliances such as water purifiers, air conditioners, refrigerators, etc., but is not limited thereto. That is, the sterilization device may be applied to various products that need to be sterilized (e.g., medical equipment).

[0234] For example, the water purifier may include a sterilizing device according to an exemplary embodiment so that the circulating water is sterilized. The sterilizing device may be arranged at a nozzle or outlet through which water circulates and can irradiate UV light. In this case, the sterilizing device may include a waterproof structure.

[0235] The curing device may include a semiconductor device according to an exemplary embodiment to cure various liquids. Liquid may be the broadest concept including various materials that cure when exposed to UV light. For example, the curing device may cure various types of resins. Alternatively, the curing device may be applied to cure cosmetics such as nail art.

[0236] The lighting device may include: a light source module having a substrate and a semiconductor device of an exemplary embodiment; a heat dissipation portion configured to dissipate heat of the light source module; and a power supply configured to process or convert an electrical signal provided from the outside to provide the electrical signal to the light source module. In addition, the lighting device may include a lamp, a headlamp, a street lamp, etc.

[0237] The display device may include a bottom cover, a reflector, a light emitting module, a light guide plate, an optical sheet, a display panel, an image signal output circuit, and a color filter. The bottom cover, the reflector, the light emitting module, the light guide plate, and the optical sheet may constitute a backlight unit.

[0238] The reflector may be arranged on the bottom cover, and the light emitting module may emit light. The light guide plate may be arranged in front of the reflector to guide the light emitted from the light emitting module forward, and the optical sheet may include a prism sheet, etc., and may be arranged in front of the light guide plate. The display panel may be arranged in front of the optical sheet, the image signal output circuit may supply the image signal to the display panel, and the color filter may be arranged in front of the display panel.

[0239] When a semiconductor device is used as a backlight unit of a display device, the semiconductor device may be used as an edge-type backlight unit or a direct-type backlight unit.

[0240] In addition to the above-mentioned light emitting diodes, the semiconductor device may also include a laser diode.

[0241] Similar to the light emitting device, the laser diode may include a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer of the above structure. In addition, the laser diode uses an electroluminescence phenomenon in which light is emitted when current flows after a p-type first conductive semiconductor and an n-type second conductive semiconductor are combined, but there is a difference in the directionality and phase of the emitted light between the light emitting device and the laser diode. That is, the laser diode can use a phenomenon called stimulated emission and constructive interference to emit light with the same phase in the same direction at a specific single wavelength (i.e., a monochromatic light beam), and using the above characteristics, the laser diode can be used for optical communications, medical equipment, semiconductor processing equipment, etc.

[0242] Examples of light receiving devices may include a photodetector, which is a transducer that detects light and converts the intensity of the detected light into an electrical signal. As photodetectors, there are photoelectric cells (silicon and selenium), optical conversion devices (cadmium sulfide and cadmium selenide), photodiodes (PDs) (e.g., PDs having a peak wavelength in a visible blind spectral region or in a true blind spectral region), phototransistors, photomultiplier tubes, phototubes (e.g., vacuum and gas-filled types), infrared (IR) detectors, etc., but the embodiments are not limited thereto.

[0243] In addition, semiconductor devices such as photodetectors can be manufactured using direct bandgap semiconductors, and their light conversion efficiency is generally excellent. Alternatively, the photodetector has a variety of structures, and includes a pin-type photodetector using a pn junction as the most common structure, a Schottky-type photodetector using a Schottky junction, and a metal-semiconductor-metal (MSM) type photodetector.

[0244] Similar to the light emitting device, the PD may include a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer of the above structure, and may be formed by a pn junction or a pin structure. The PD operates by applying a reverse bias or a zero bias, and when light is incident on the PD, electrons and holes are generated, and thus current flows. At this time, the amount of current may be approximately proportional to the intensity of the light incident on the PD.

[0245] A photovoltaic cell or solar cell is a type of PD and can convert light into electric current. Similar to a light emitting device, a solar cell may include a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer of the above structure.

[0246] Furthermore, the solar cell can be used as a rectifier of an electronic circuit by using the rectification characteristics of a general diode of a pn junction, and can be applied to an oscillation circuit or the like by being used in a microwave circuit.

[0247] In addition, the semiconductor devices described above are not necessarily implemented by semiconductors, and in some cases, the semiconductor devices may also include metal materials. For example, semiconductor devices such as light receiving devices may be implemented using at least one of Ag, Al, Au, In, Ga, N, Zn, Se, P, and As, or may be implemented using semiconductor materials doped with p-type or n-type dopants or intrinsic semiconductor materials.

[0248] Although the present invention has been described primarily with reference to exemplary embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments, and that various modifications and applications can be designed by those skilled in the art to which the present invention belongs without departing from the gist of the present invention. For example, each component specifically shown in the exemplary embodiments can be modified and implemented. It should be understood that differences associated with these modifications and applications will fall within the scope of the present invention as defined by the appended claims.

Claims

1. A semiconductor device, characterized in that: include: A semiconductor structure comprising a first conductive semiconductor layer, a second conductive semiconductor layer, an active layer arranged between the first conductive semiconductor layer and the second conductive semiconductor layer, a plurality of first recesses, and a second recess, wherein the plurality of first recesses and the second recesses are arranged to pass through the second conductive semiconductor layer and the active layer to a certain area of ​​the first conductive semiconductor layer, and the second recess is arranged between the plurality of first recesses; a plurality of first electrodes disposed within the plurality of first recesses and electrically connected to the first conductive semiconductor layer; a plurality of second electrodes electrically connected to the second conductive semiconductor layer; as well as a reflective layer disposed in the second recess and covering a portion of a side surface and a lower surface of the plurality of second electrodes, The semiconductor structure includes a second region arranged between a side surface of the semiconductor structure and the second recess.

2. The semiconductor device according to claim 1, wherein: A separation distance between a side surface of the semiconductor structure and the second recess is in a range of 1.0 μm to 10 μm.

3. The semiconductor device according to claim 1, wherein: The plurality of second electrodes include an edge electrode disposed in the second region.

4. The semiconductor device according to any one of claims 1 to 3, characterized in that: The first direction is a direction perpendicular to the thickness direction of the semiconductor structure; with respect to the maximum area of ​​the semiconductor structure in the first direction, the areas of the plurality of second recesses are in a range of 4% to 10%.

5. The semiconductor device according to any one of claims 1 to 3, characterized in that: The protruding height H1 of the second recess satisfies the relational expression: H1=W4×tan(θ1); wherein W4 is the distance from the midpoint between the first recess and the second recess adjacent to each other to the upper surface of the second recess, and θ1 is in the range of 0.5 degrees to 5.0 degrees.

6. The semiconductor device according to any one of claims 1 to 3, characterized in that: The reflective layer is arranged in a range of 30% to 40% with respect to a current density of the first electrode.

7. The semiconductor device according to any one of claims 1 to 3, characterized in that: A third concave portion is provided at an edge of the semiconductor structure; and the semiconductor device includes a side reflection portion formed inside the third concave portion.

8. The semiconductor device according to any one of claims 1 to 3, characterized in that: The first direction is a direction perpendicular to the thickness direction of the semiconductor structure; with respect to the maximum area of ​​the semiconductor structure in the first direction, the area of ​​the reflective layer is in the range of 46% to 70%.

9. The semiconductor device according to any one of claims 1 to 3, characterized in that: The semiconductor device includes a first insulating layer arranged in the second recess, and the reflective layer is arranged on the first insulating layer in the second recess; the reflective layer covers a first separation distance between the second electrode and the first insulating layer, and contacts with a side surface and a lower surface of the first insulating layer and a lower surface and a side surface of the second electrode within the first separation distance.

10. A semiconductor device package, characterized in that: A semiconductor device comprising any one of claims 1 to 9.

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