Light-emitting element and light-emitting device comprising same

Abstract

The present invention relates to a light-emitting element and a light-emitting device comprising same. Disclosed is a light-emitting element comprising: a first conductivity-type semiconductor layer; a second conductivity-type semiconductor layer disposed on the first conductivity-type semiconductor layer; and an active layer disposed between the first conductivity-type semiconductor layer and the second conductivity-type semiconductor layer, wherein the first conductivity-type semiconductor layer includes a bunker layer in which a content profile of a first material according to vertical depth appears in a recessed form due to a decrease in content of the first material.

Description

Light-emitting element and light-emitting device including the same

[0001] The present invention relates to a light-emitting element and a light-emitting device including the same.

[0002] A light emitting diode (LED) is a type of light emitting device that emits light when current is applied. The LED is formed by growing epitaxial layers on a substrate, and includes an N-type semiconductor layer, a P-type semiconductor layer, and an active layer interposed therebetween. An N-electrode pad is formed on the N-type semiconductor layer, and a P-electrode pad is formed on the P-type semiconductor layer, so that the LED is driven by being electrically connected to an external power source through the electrode pads. At this time, current flows from the P-electrode pad through the semiconductor layers to the N-electrode pad.

[0003] Light-emitting diodes can convert electrical signals into light, such as infrared, visible light, and ultraviolet light, by utilizing the properties of compound semiconductors.

[0004] As light-emitting diodes increase in luminous efficiency, they are being applied to various fields including display devices and lighting devices. The size of light-emitting diodes is also gradually decreasing, and mini LEDs and micro LEDs are being used.

[0005] A display device using light emitting diodes can be obtained by forming structures of individually grown red (R), green (G) and blue (B) light emitting diodes (LEDs) on a final substrate.

[0006] The purpose of the present invention is to provide a light-emitting element with improved luminous efficiency and a light-emitting device including the same.

[0007] The purpose of the present invention is to provide a light-emitting element and a light-emitting device including the same, which can improve the electrical characteristics of the light-emitting element by enabling low resistance at high current even when the chip size is miniaturized.

[0008] A light-emitting device according to one embodiment of the present invention comprises a first conductive semiconductor layer, a second conductive semiconductor layer disposed on the first conductive semiconductor layer, and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer, wherein the first conductive semiconductor layer may include a bunker layer in which the content of a first material is reduced so that the content profile of the first material according to the vertical depth appears in a sunken form.

[0009] In one embodiment, the bunker layer can be formed within 3 um from the active layer.

[0010] In one embodiment, the bunker layer may form a first variable section in which the content of the first material is variable and a second variable section spaced apart from the first variable section in which the content of the first material is variable.

[0011] In one embodiment, the rate of change in the content of the first material according to the change in distance from the active layer in the first variable section may be different from the rate of change in the content of the first material according to the change in distance from the active layer in the second variable section.

[0012] In one embodiment, the second variable section may be closer to the active layer than the first variable section.

[0013] In one embodiment, the difference between the maximum and minimum values ​​of the content of the first material in the second variable section may be greater than the difference between the maximum and minimum values ​​of the content of the first material in the first variable section.

[0014] In one embodiment, the bunker layer further includes a second material, and a third material, wherein the first material may be Al, the second material may be In, and the third material may be Ga.

[0015] In one embodiment, the difference between the content of the first material and the content of the third material in the bunker layer may be smaller than the difference between the content of the first material and the content of the second material.

[0016] In one embodiment, the median value of the content of the first material and the content of the second material in the bunker layer may be included in the content area of ​​the first material in the first and second variable sections.

[0017] In one embodiment, within 3 um from the bunker layer, at least two intersections may be formed where the magnitude relationship between the content of the first material and the content of the second material is different.

[0018] In one embodiment, the content of the first material at the intersection may be greater than the content of the first material in the bunker layer (112).

[0019] In one embodiment, the bunker layer may include a first region and a second region having different concentrations of the first challenge-type dopant.

[0020] In one embodiment, the first region is closer to the active layer than the second region, and the concentration of the first conductive dopant in the first region may be greater than the concentration of the first conductive dopant in the second region.

[0021] In one embodiment, the bunker layer further includes a third region, wherein the first region can be disposed between the second region and the third region.

[0022] In one embodiment, the concentration of the first conductive dopant in the first region may be greater than the concentration of the first conductive dopant in the third region.

[0023] In one embodiment, the thickness of the third region may be less than the thickness of the second region.

[0024] According to one embodiment of the present invention, a light-emitting device includes a first conductive semiconductor layer; a second conductive semiconductor layer disposed on the first conductive semiconductor layer; and an active layer disposed between the first conductive semiconductor layer (110) and the second conductive semiconductor layer, wherein a content profile of each component according to depth from a surface of the second conductive semiconductor layer downward may include a bunker in which the content of the first material decreases within the first conductive semiconductor layer, and the content profile of the first material according to the vertical depth appears in a sunken form.

[0025] In one embodiment, the bunker may include first and second inclined surfaces having variable contents of the first material at both ends.

[0026] In one embodiment, the slope of the first slope may be different from the slope of the second slope.

[0027] In one embodiment, the length of the second inclined surface may be longer than the length of the first inclined surface.

[0028] In one embodiment, the first slope may be closer to the active layer than the second slope.

[0029] In one embodiment, within 3 um from the bunker, the content profile of the first material and the content profile of the second material may have at least two intersection points.

[0030] The present invention can provide a light-emitting element with improved luminous efficiency and a light-emitting device including the same.

[0031] The present invention can provide a light-emitting element and a light-emitting device including the same, which can improve the electrical characteristics of the light-emitting element by enabling low resistance at high current even when the chip size is miniaturized.

[0032] FIG. 1 is a cross-sectional view showing a light-emitting device according to one embodiment of the present invention.

[0033] Fig. 2 is a cross-sectional view showing the epilayer of the light emitting element of Fig. 1.

[0034] Figure 3 is a profile showing the depth-dependent component content distribution for the epilayer of Figure 2.

[0035] In the following description, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of various embodiments or implementations of the present disclosure. As used herein, the terms "embodiment" and "implementation" are interchangeable to refer to non-limiting examples of devices or methods that utilize one or more of the inventive concepts disclosed herein. However, it will be apparent that various embodiments may be practiced without utilizing these specific details or using one or more equivalent arrangements. In other instances, well-known structures and devices are shown in block diagram form to avoid unnecessarily obscuring the various embodiments. Furthermore, while the various embodiments may vary from one another, they are not necessarily exclusive. For example, specific features, configurations, and characteristics of an embodiment may be utilized or implemented in other embodiments without departing from the scope of the inventive concepts.

[0036] Unless otherwise specified, the illustrated embodiments should be understood to provide exemplary features of varying details of some ways in which the concepts of the present invention may be practically implemented. Therefore, unless otherwise specified, the features, components, modules, layers, membranes, panels, regions, and / or aspects (hereinafter, individually or collectively referred to as "elements") of the various embodiments may be differently combined, separated, interchanged, and / or rearranged without departing from the scope of the concepts of the present invention.

[0037] The use of cross-hatching and / or shading in the accompanying drawings is generally provided to clarify boundaries between adjacent elements. As such, the presence or absence of cross-hatching or shading, unless expressly stated, does not imply or indicate any preference or requirement for any particular material, material properties, dimensions, proportions, commonality between the illustrated elements, and / or any other features, properties, or characteristics of the elements. Furthermore, in the accompanying drawings, the dimensions and relative sizes of elements may be exaggerated for clarity and / or illustrative purposes. When embodiments are implemented differently, certain process sequences may be performed differently from the illustrated sequence. For example, two consecutively illustrated processes may be performed substantially simultaneously or in a reverse order from the illustrated sequence. Furthermore, like reference numerals designate like elements.

[0038] When an element, such as a layer, is referred to as being "on," "connected to," or "joined to" another element or layer, the element may be directly on, connected to, or joined to the other element or layer, or there may be intervening elements or layers present. However, when an element or layer is referred to as being "directly on," "directly connected to," or "directly joined to" another element or layer, there are no intervening elements or layers present. For this purpose, the term "connected" may refer to physical, electrical, and / or fluidic connections, with or without intervening elements. Furthermore, the DR1-axis, DR2-axis, and DR3-axis are not limited to the three axes of a Cartesian coordinate system, such as the x, y, and z-axes, and may be interpreted in a broader sense. For example, the DR1-axis, DR2-axis, and DR3-axis may be perpendicular to one another, or may represent different directions that are not perpendicular to one another. For purposes of this disclosure, “at least one of X, Y, and Z” and “at least one selected from the group consisting of X, Y, and Z” may be interpreted as only X, only Y, only Z, or any combination of two or more of X, Y, and Z, such as, for example, XYZ, XYY, YZ, and ZZ. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0039] Although the terms "first," "second," and the like may be used herein to describe various types of elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. Therefore, the first element discussed below may be referred to as the second element without departing from the teachings of the present disclosure.

[0040] Spatially relative terms such as "beneath," "beneath," "directly beneath," "lower," "above," "upper," "above," "higher than," "side" (as in, for example, a "side wall"), and the like may be used for descriptive purposes and thereby to describe the relationship of one element to other element(s) as depicted in the drawings. Spatially relative terms are intended to encompass different orientations of the device in use, operation, and / or manufacture in addition to the orientations depicted in the drawings. For example, if the device in the drawings were turned over, an element described as "beneath" or "beneath" another element or feature would then be oriented "above" the other element or feature. Therefore, the exemplary term "beneath" can encompass both orientations above and below. Furthermore, the device can be oriented differently (e.g., rotated 90° or oriented in other orientations), and thus the spatially relative descriptors used herein can also be interpreted accordingly.

[0041] The terminology used herein is for the purpose of describing particular embodiments and is not limiting. The singular forms "a," "an," and "the" as used herein also include the plural forms unless the context clearly dictates otherwise. Furthermore, the terms "comprises," "comprising," "includes," and / or "comprising" as used herein specify the presence of stated features, integers, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Furthermore, the terms "substantially," "about," and other similar terms as used herein are used as terms of approximation rather than degrees, and as such, are used to describe inherent deviations from measured, calculated, and / or provided values ​​that would be recognized by one of ordinary skill in the art.

[0042] Various embodiments are described below with reference to cross-sectional and / or exploded illustrations, which are schematic illustrations of idealized embodiments and / or intermediate structures. As such, variations from the shapes of the illustrated drawings may be expected, for example, as a result of manufacturing techniques and / or tolerances. Therefore, the embodiments disclosed herein should not necessarily be construed as limited to the shapes of specific illustrated regions, but should be construed to include, for example, deviations in shape resulting from manufacturing. In this way, the regions depicted in the drawings may be schematic in nature, and the shapes of these regions may not reflect the actual shapes of regions of the device, and as such, are not necessarily intended to have a limiting meaning.

[0043] As is conventional in the art, some embodiments may be illustrated and described in the accompanying drawings in terms of functional blocks, units, and / or modules. Those skilled in the art will appreciate that these blocks, units, and / or modules are physically implemented by electronic (or optical) circuits such as logic circuits, discrete components, microprocessors, wiring circuits, memory elements, and wiring connections formed using semiconductor-based or other manufacturing techniques. When the blocks, units, and / or modules are implemented by microprocessors or other similar hardware, they may be programmed and controlled using software (e.g., microcode) to perform the various functions discussed herein, and optionally, may be driven by firmware and / or software. Furthermore, each block, unit, and / or module may be implemented by dedicated hardware, or by a combination of dedicated hardware for performing some functions and processors (e.g., one or more programmed processors and associated circuitry) for performing other functions. Additionally, the blocks, units, and / or modules of some embodiments may be physically separated into two or more interacting and individual blocks, units, and / or modules without departing from the scope of the present invention. Additionally, the blocks, units, and / or modules of some embodiments may be physically combined into more complex blocks, units, and / or modules without departing from the scope of the present invention.

[0044] Unless otherwise defined, all terms (including technical or scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Terms defined in commonly used dictionaries, such as terms defined in commonly used dictionaries, should be interpreted to have a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an idealistic or overly formal sense unless explicitly defined herein.

[0045] A light-emitting device (100) according to an embodiment of the present invention may include a first conductive semiconductor layer (110), a second conductive semiconductor layer (120) disposed on the first conductive semiconductor layer (110), and an active layer (130) disposed between the first conductive semiconductor layer (110) and the second conductive semiconductor layer (120). Hereinafter, a preferred embodiment of the present invention will be described in more detail with reference to the attached drawings.

[0046] The above first conductive semiconductor layer (110) is a semiconductor layer doped with the first conductive type and can be formed by growing on a growth substrate. The growth substrate is a substrate for growing a semiconductor layer and can have various configurations, and for example, can be a gallium arsenide substrate.

[0047] The first conductive semiconductor layer (110) may include a phosphide or nitride semiconductor such as (Al, Ga, In)P or (Al, Ga, In)N, and may be grown using a method such as MOCVD, MBE, HVPE, etc. As an example, the first conductive semiconductor layer (110) may be (Al) doped with the first conductive type. x Ga (1-x) ) 0.5 In 0.5 It may be a semiconductor layer of P's ignition system.

[0048] The first conductive semiconductor layer (110) may be doped with a first conductive dopant. For example, the first conductive dopant may be an n-type dopant. The n-type dopant may include at least one type of impurity such as Si, Te, B, P, As, or Sb. The first conductive semiconductor layer (110) may include a single type of dopant or may include multiple types of dopants. For example, the first conductive semiconductor layer (110) may be doped with Si, Te, or a mixture of Si and Te. However, the present invention is not limited thereto, and the first conductive semiconductor layer (110) may be doped with an opposite conductive dopant such as a p-type dopant. The p-type dopant may include at least one type of impurity such as Mg or C (carbon).

[0049] The second conductive semiconductor layer (120) is a semiconductor layer disposed on top of the first conductive semiconductor layer (110), and may be a semiconductor layer doped with a second conductive type opposite to the first conductive type.

[0050] The second conductive semiconductor layer (120) may include a phosphide-based or nitride-based semiconductor such as (Al, Ga, In)P or (Al, Ga, In)N, and may be grown using a technique such as MOCVD, MBE, or HVPE. For example, the second conductive semiconductor layer (120) may be a phosphide-based semiconductor layer of GaP doped with the second conductive type.

[0051] The second conductive semiconductor layer (120) may be doped with a second conductive dopant having a conductive type opposite to that of the first conductive semiconductor layer (120). For example, the second conductive dopant may be a p-type dopant. The p-type dopant may include at least one type of impurity such as Mg or C (carbon). For example, the second conductive semiconductor layer (120) may be doped to be p-type by including the same impurities such as Mg or C (carbon). The second conductive semiconductor layer (120) may be configured to include one Group III element. The present invention is not limited thereto, and the second conductive semiconductor layer (120) may be doped to be opposite in conductive type by including an n-type dopant. The n-type dopant may include at least one type of impurity such as Si, Te, B, P, As, or Sb.

[0052] The above active layer (130) is a light-emitting layer disposed between the first conductive semiconductor layer (110) and the second conductive semiconductor layer (120), and can have various configurations. The active layer (130) may include a phosphide or nitride semiconductor such as (Al, Ga, In)P or (Al, Ga, In)N, and may be grown using a technique such as MOCVD, MBE, or HVPE. For example, the active layer (130) may include In x Ga y Al z P, In x Ga y It can have any one of the compositions of P.

[0053] The above active layer (130) can be formed to a thickness of 150 nm to 250 nm.

[0054] Additionally, the active layer (130) may include a quantum well structure (QW) including at least two barrier layers and at least one well layer, and further may include a multiple quantum well structure (MQW) including a plurality of barrier layers and a plurality of well layers.

[0055] The wavelength of light emitted from the above active layer (130) can be controlled by controlling the composition ratio of the material constituting the well layer. In this case, the well layer may commonly contain the same element and may contain In. The well layer may be In x Ga y Al z P(x+y+z=1), In x Ga y It can be formed as a layer having a composition of one of P(x+y=1) and a thickness of 3 to 7 nm.

[0056] The above barrier layer is In x Ga y Al z It can be a layer having a composition of P. Here, x, y, and z can satisfy the relationship x*0.8≤y+z≤x*1.2 or the relationship x+y+z=1. In addition, z can have a composition of 0.15≤z≤0.4.

[0057] The above barrier layer may be formed as an undoped layer to improve the quality of the thin film, or may be formed as an n-type doped layer to improve electron injection.

[0058] The thickness of the above barrier layer may be formed to a thickness thicker than that of the well layer, and may preferably be 10 nm or more.

[0059] When the above well layer and barrier layer are formed as a pair, the active layer (130) may be composed of 10 to 40 pairs of well layers and barrier layers. The peak wavelength of light emitted from the active layer (130) may be in the range of 600 to 700 nm.

[0060] Meanwhile, referring to FIG. 1, the second conductive semiconductor layer (120) may be partially etched to expose at least a portion of the first conductive semiconductor layer (110). Accordingly, the light-emitting element (100) may include a first electrode (140) disposed on the exposed surface of the first conductive semiconductor layer (110) and a second electrode (150) disposed on one surface of the second conductive semiconductor layer (120). Power may be applied through the first electrode (140) and the second electrode (150). The present invention is not limited thereto, and the first conductive semiconductor layer (110) may be partially etched to expose at least a portion of the second conductive semiconductor layer (120). Accordingly, the light-emitting element (100) may include a second electrode (150) disposed on an exposed surface of the second conductive semiconductor layer (120) and a first electrode (140) disposed on one surface of the first conductive semiconductor layer (110). Power may be applied through the first electrode (140) and the second electrode (150). Although Fig. 1 illustrates an example in which the light-emitting element (100) is configured in a flip-chip form, the present invention is not limited thereto, and various modified forms such as vertical and horizontal forms are of course possible.

[0061] In the present invention, the first conductive semiconductor layer (110) may be formed of multiple layers. For example, the first conductive semiconductor layer (110) may include a first-first conductive sub-semiconductor layer (113) and a first-second conductive sub-semiconductor layer (111).

[0062] The above 1-1 conductive sub-semiconductor layer (113) may include a phosphide semiconductor of (Al, Ga, In)P or a nitride semiconductor of (Al, Ga, In)N, and may be doped with a first conductive dopant. For example, the above 1-1 conductive sub-semiconductor layer (113) may include (Al x Ga (1-x) ) 0.5 In 0.5It may be a semiconductor layer of P. The above x may have a value of 0.8 to 0.6.

[0063] The above 1-1 conductive sub-semiconductor layer (113) may be a layer doped with an n-type dopant that serves to generate and supply electrons. Si may be used as the n-type dopant, but is not limited thereto, and Te may also be used.

[0064] The above 1-1 challenge type sub-semiconductor layer (113) is a main semiconductor layer with a conductivity of 1E18 to 1E20 atoms / cm 3 It may be a layer having a doping concentration in the range.

[0065] Among the first-first challenge-type sub-semiconductor layers (113), the surface layer (114) may have a textured surface (S). Referring to FIG. 1, a portion of the surface layer (114) may be etched to form unevenness (PT) on the surface (S). The surface layer (114) may be a layer having a higher doping concentration than the doping concentration of the main semiconductor layer.

[0066] The above 1-2 conductive sub-semiconductor layer (111) can be placed between the 1-1 conductive sub-semiconductor layer (113) and the active layer (130).

[0067] The above 1-2 challenge type sub-semiconductor layer (111) is In doped with a 1st challenge type dopant. x Al (1-x) It may be a layer composed of P, where x may have a composition of 0.4≤x≤0.6, and the doping concentration is 7E17 atoms / cm 3 More than 3E18 atoms / cm 3 It may be less than or equal to 200 nm in thickness.

[0068] The above 1-2 conductive sub-semiconductor layer (111) may be a cladding layer that allows electrons and holes to recombine within the active layer (130) with a higher energy band gap than the well layer of the active layer (130). In addition, the 1-2 conductive sub-semiconductor layer (111) may have a higher energy band gap or a higher aluminum content than the 1-1 conductive sub-semiconductor layer (113). Accordingly, the speed of electrons injected into the well layer can be controlled. The 1-2 conductive sub-semiconductor layer (111) may include a dopant material different from the 1-1 conductive sub-semiconductor layer (113). Therefore, a material having a relatively higher ionization energy may be included in a region close to the active layer (130), thereby increasing electron affinity, and thereby allowing electrons to be formed more efficiently. The 1-2nd conductive sub-semiconductor layer (111) can use a Te source, which is an n-type dopant, as the 1st conductive dopant. By using a Te source, excellent luminous properties can be achieved.

[0069] Meanwhile, the light-emitting element (100) may further include an electron control layer (160) between the first-second conductive sub-semiconductor layer (111) and the active layer (130).

[0070] The above electron control layer (160) may be an undoped InAlGaP layer that controls the speed at which electrons reach the active layer (130) to obtain a fast recombination speed. The thickness of the electron control layer (160) may be controlled together with the thickness of the diffusion barrier layer (170) described below.

[0071] The above electronic control layer (160) is a layer with a lower doping concentration than the first conductive semiconductor layer (110), and is made of In x Ga y Al zIt can be formed as P. Here, x, y, and z can satisfy the relationship x*0.8≤y+z≤x*1.2 or the relationship x+y+z=1. In addition, z can have a composition of 0.15≤z≤0.4. Since the electron control layer (160) has such an Al composition, light generated from the light-emitting element (100) is prevented from being absorbed in the electron control layer (160), so that light extraction efficiency can be improved.

[0072] Meanwhile, the light emitting element (100) may further include a diffusion barrier layer (170) between the second conductive semiconductor layer (120) and the active layer (130). The diffusion barrier layer (170) may be an undoped InAlGaP layer that controls the speed at which holes reach the active layer (130). In addition, the diffusion barrier layer (170) may be a layer that protects the active layer (130) from damage due to diffusion caused by the second conductive dopant doping of the second conductive semiconductor layer (120).

[0073] That is, the diffusion barrier layer (170) may be arranged to prevent the second conductive dopant from diffusing excessively into the active layer (130), In x Ga y Al z It can be formed by P. Here, x, y, and z can satisfy the relationship x*0.8≤y+z≤x*1.2 or the relationship x+y+z=1. In addition, z can have a composition of 0.15≤z≤0.4.

[0074] The above diffusion barrier layer (170) may be an undoped layer and may have a lower doping concentration than the second conductive semiconductor layer (120). In addition, the diffusion barrier layer (170) may be formed by a combination of three group III elements.

[0075] The thickness of the diffusion barrier layer (170) is set to 50 nm or more, thereby effectively preventing the second conductive dopant from diffusing into the active layer (130), and improving reliability and the reduction in low current applied voltage and reverse voltage current characteristics. In addition, it is preferable that the diffusion barrier layer (170) be formed to a thickness of 400 nm or less.

[0076] Meanwhile, the second conductive semiconductor layer (120) may also be formed of multiple layers. For example, the second conductive semiconductor layer (120) may include a second-first conductive sub-semiconductor layer (122) and a second-second conductive sub-semiconductor layer (121).

[0077] The above 2-1 conductive sub-semiconductor layer (122) may be doped with a 2nd conductive dopant (Mg or C, etc.) as a GaP layer. The above 2-1 conductive sub-semiconductor layer (122) may be formed with a thickness of 0.5 to 10 μm depending on the structure as a main semiconductor layer for forming and supplying holes.

[0078] The above 2-1 challenge type sub-semiconductor layer (122) may use either Mg or C (carbon) as a dopant, or both materials may be injected and used simultaneously. The doping concentration of Mg is 2E17 to 4E18 atoms / cm 3 It can have a value in the range of . The thickness of the 2-1 challenge type sub-semiconductor layer (122) can be 400 nm or more, through which sufficient supply of holes can be achieved and the effect of current distribution can be implemented.

[0079] Additionally, the second-first challenge-type sub-semiconductor layer (122) may be configured to include at least one group III element.

[0080] The above 2-2 conductive sub-semiconductor layer (121) can be placed between the above 2-1 conductive sub-semiconductor layer (122) and the active layer (130).

[0081] The above-mentioned 2-2 conductive sub-semiconductor layer (121) may be an InAlP layer doped with a second conductive dopant, and may be a cladding layer designed to prevent electrons from overflowing. The second conductive dopant may use Mg or C (CBr4).

[0082] Specifically, the second-second conductive sub-semiconductor layer (121) is In doped with a second conductive dopant. x Al (1-x) It may be a layer composed of P, where x may have a composition of 0.4≤x≤0.6, and the doping concentration is 8E17atoms / cm 3 It could be as follows:

[0083] The thickness of the above-mentioned 2-2 conductive sub-semiconductor layer (121) may be formed to a thickness of 300 nm or more and 500 nm or less. Preferably, the thickness of the above-mentioned 2-2 conductive sub-semiconductor layer (121) may be thicker than the thickness of the active layer (130).

[0084] The above 2-2 challenge type sub-semiconductor layer (121) can be formed of two group III elements and can be a layer having a higher band gap energy than the layers disposed below and above it.

[0085] Alternatively, the 2-2 conductive sub-semiconductor layer (121) may be a layer having the highest band gap energy among the layers constituting the light emitting element (100). Alternatively, the 2-2 conductive sub-semiconductor layer (121) may have a lower refractive index than the layers disposed below and above it. Alternatively, the 2-2 conductive sub-semiconductor layer (121) may have the lowest refractive index among the layers constituting the light emitting element (100). Through this, electrons may be prevented from moving and causing non-radiative recombination. In addition, light extraction efficiency may be improved due to the low refractive index arrangement of the 2-2 conductive sub-semiconductor layer (121).

[0086] The second conductive semiconductor layer (120) may further include a second-third conductive sub-semiconductor layer (123). The second-third conductive sub-semiconductor layer (123) may be a contact layer disposed on the second-first conductive sub-semiconductor layer (122) and in contact with the second electrode (150).

[0087] The above 2-3 conductive sub-semiconductor layer (123) may be an ohmic contact layer for securing ohmic characteristics with the second electrode (150). The above 2-3 conductive sub-semiconductor layer (123) may be a GaP layer doped with a 2nd conductive dopant.

[0088] The above 2-3 challenge type sub-semiconductor layer (123) has a high doping concentration (e.g., 7E17 atoms / cm) for ohmic contact with the second electrode (150). 3 It may be a layer having a (above) conductivity type. The 2-3 conductive sub-semiconductor layer (123) may have a higher doping concentration than the 2-1 conductive sub-semiconductor layer (122), and accordingly, the ohmic characteristics with respect to the second electrode (150) may be improved.

[0089] Mg or C (carbon) may be used as the second challenge dopant. Either Mg or carbon may be used as the second challenge dopant, or both materials may be injected simultaneously and used together.

[0090] The thickness of the 2-3 conductive sub-semiconductor layer (123) may be 100 nm or less. Since the 2-3 conductive sub-semiconductor layer (123) has a relatively high doping concentration, defects exist within the semiconductor layer due to the dopant, and when the thickness increases, light absorption may occur due to these defects, which may reduce light efficiency. Therefore, by forming the thickness of the 2-3 conductive sub-semiconductor layer (123) to 100 nm or less, a decrease in light efficiency due to light absorption can be prevented. The 2-3 conductive sub-semiconductor layer (123) may be omitted as an optional configuration.

[0091] Meanwhile, the first conductive semiconductor layer (110) may further include a bunker layer (112) to increase the residence time of electrons moving toward the active layer (130).

[0092] The bunker layer (112) may be a layer in which the content of the first material decreases within the first conductive semiconductor layer (110) so that the content profile of the first material according to the vertical depth appears in a sunken form. The bunker layer (112) may be arranged between the 1-1 conductive sub-semiconductor layer (113) and the 1-2 conductive sub-semiconductor layer (111). The first material may be one of the materials constituting the first conductive semiconductor layer (110). In this case, the material may mean a component constituting the first conductive semiconductor layer (110) excluding the first conductive dopant.

[0093] For example, the first conductive semiconductor layer (110) may include a first material, a second material, a third material, and a fourth material, wherein the first material may be aluminum (Al), the second material may be indium (In), the third material may be gallium (Ga), and the fourth material may be phosphorus (P). The first material may be a material having a relatively small atomic weight among the materials constituting the first conductive semiconductor layer (110). The bunker layer (112) may also include the first material, the second material, the third material, and the fourth material.

[0094] That is, the bunker layer (112) may be a layer having a lower content of the first material compared to other regions within the first conductive semiconductor layer (110).

[0095] The above bunker layer (112) may contain the same material as the 1-1 conductive sub-semiconductor layer (113), but the composition ratio may be different.

[0096] For example, the above bunker layer (112) is (Al x Ga (1-x) ) 0.5 In 0.5As a layer consisting of P, x can have a value in the range of 0.3 to 0.5.

[0097] The content of the first material in the above bunker layer (112) may be less than the content of the first material in the first-1 conductive sub-semiconductor layer (113). In this case, the first material may be Al.

[0098] In addition, the content ratio of the first material and the third material (=content of the first material / content of the third material) in the bunker layer (112) may be smaller than the content ratio of the first material and the third material in the 1-1 conductive semiconductor layer (113). In this case, the first material may be Al, and the third material may be Ga.

[0099] The above bunker layer (112) can be formed within 3 um from the active layer (130). That is, referring to FIG. 3, the gap D between the boundary of the bunker layer (112) and the active layer (130) can be 3 um or less.

[0100] The above bunker layer (112) is a layer in which the content of the first material is lower than that of other adjacent layers, and can form a first variable section (CH1) in which the content of the first material is variable, and a second variable section (CH2) spaced apart from the first variable section (CH1) and in which the content of the first material is variable.

[0101] Referring to FIG. 3, the first variable section (CH1) is a region in which the content of the first material is variable, and may be a region in which the content of the first material increases in a direction away from the active layer (130). The second variable section (CH2) is a region in which the content of the first material is variable, and may be a region in which the content of the first material decreases in a direction away from the active layer (130). The second variable section (CH2) may be a region closer to the active layer (130) than the first variable section (CH1).

[0102] As illustrated in FIG. 3, the content profile of the first material according to depth in the bunker layer (112) may be depicted as a puddle shape (sunken shape) by the first variable section (CH1) and the second variable section (CH2). Here, the depth may be the distance from the upper surface of the second conductive semiconductor layer (120) based on the direction from the upper surface of the second conductive semiconductor layer (120) toward the active layer (130).

[0103] The thickness of the first variable section (CH1) and the thickness of the second variable section (CH2) may be the same or different from each other.

[0104] In the first variable section (CH1), the maximum and minimum values ​​of the first material content may appear at both end boundaries of the first variable section (CH1). Similarly, in the second variable section (CH2), the maximum and minimum values ​​of the first material content may appear at both end boundaries of the second variable section (CH2).

[0105] The maximum value of the content of the first substance in the first variable section (CH1) may be the same as or different from the maximum value of the content of the first substance in the second variable section (CH2). The minimum value of the content of the first substance in the first variable section (CH1) may be the same as or different from the minimum value of the content of the first substance in the second variable section (CH2).

[0106] For example, the difference between the maximum and minimum contents of the first substance in the second variable section (CH2) may be greater than the difference between the maximum and minimum contents of the first substance in the first variable section (CH1).

[0107] The central section located between the first variable section (CH1) and the second variable section (CH2) may be a section in which the content of the first material has a value within a certain range and is constant. The content of the first material within the central section may vary somewhat, but since it fluctuates slightly within a certain range, it may be understood as a section having a constant content of the first material. The minimum value of the content of the first material within the bunker layer (112) may have a value that is 0.55 to 0.6 times the maximum value.

[0108] The rate of change in the content of the first material according to the change in distance from the active layer (130) in the first variable section (CH1) may be different from the rate of change in the content of the first material according to the change in distance from the active layer (130) in the second variable section (CH2).

[0109] In the first variable section (CH1), the content change rate of the first material may be determined by the difference between the maximum and minimum contents of the first material at the thickness and boundary of the first variable section (CH1). In the second variable section (CH2), the content change rate of the first material may be determined by the difference between the maximum and minimum contents of the first material at the thickness and boundary of the second variable section (CH2). Since the content of the first material in the first variable section (CH1) increases with depth, the content gradient of the first material may have a positive value, and since the content of the first material in the second variable section (CH2) decreases with depth, the Al content gradient may have a negative value. Here, the content change rate of the first material may mean the absolute value of the content gradient of the first material.

[0110] Referring again to FIG. 3, the difference (G1) between the content of the first material and the content of the third material in the bunker layer (112) may be smaller than the difference (G2) between the content of the first material and the content of the second material.

[0111] In addition, the median values ​​of the content of the first material and the content of the second material in the bunker layer (112) may be included in the content area of ​​the first material in the first and second variable sections (CH1, CH2). Referring to FIG. 3, the median values ​​of the content of the first material and the content of the second material in the bunker layer (112) are depicted by a virtual dotted line (M), and the dotted line (M) may intersect with the content area of ​​the first material in the first variable section (CH1). That is, the median values ​​of the content of the first material and the content of the second material in the bunker layer (112) may be included in the content area of ​​the first material in the first variable section (CH1). Similarly, the dotted line (M) may intersect with the content area of ​​the first material in the second variable section (CH2). That is, the central value of the content of the first material and the content of the second material in the bunker layer (112) may be included in the content area of ​​the first material in the second variable section (CH2).

[0112] Referring again to FIG. 3, within 3 μm from the bunker layer (112), at least two intersections (CR1, CR2) where the magnitude of the content of the first material and the content of the second material differ can be formed. The two intersections (CR1, CR2) can be formed in the first-second conductive sub-semiconductor layer (111).

[0113] In the region between the two intersections (CR1, CR2), the content of the first material may be greater than the content of the second material. Outside the intersections (CR1, CR2), the content of the first material may be less than the content of the second material.

[0114] The content of the first material at the above intersection (CR1, CR2) may be greater than the content of the first material in the bunker layer (112).

[0115] Meanwhile, the bunker layer (112) may include a first region (112a) and a second region (112b) having different concentrations of the first conductive dopant. As shown in FIG. 3, the first conductive dopant is Si, but the present invention is not limited thereto.

[0116] The first region (112a) may be a region closer to the active layer (130) than the second region (112b). The first region (112a) may be closer to the active layer (130) than the second region (112b).

[0117] The first region (112a) is a region in which the first conductive type dopant is doped at a high concentration, and may be a contact layer that contacts the first electrode (140). That is, the second conductive type semiconductor layer (120), the active layer (130), and a portion of the first conductive type semiconductor layer (110) may be etched to expose the first region (112a), and the first electrode (140) may be brought into contact with the exposed first region (112a). The first region (112a) may have a thickness of 5E18 atoms / cm to serve as a contact layer. 3 This may be a layer to which a high doping concentration is applied. The thickness of the first region (112a) may be formed to be approximately 500 nm. However, this is not necessarily limited thereto, and contact with the first electrode (140) may be formed in another region of the first conductive semiconductor layer (110).

[0118] The concentration of the first conductive type dopant in the first region (112a) may be greater than the concentration of the first conductive type dopant in the second region (112b). The concentration of the first conductive type dopant in the first region (112a) may be greater than the concentration of the first conductive type dopant in the 1-1 conductive type sub-semiconductor layer (113).

[0119] The second region (112a) is a region arranged between the first region (112a) and the 1-1 conductive sub-semiconductor layer (113), and the concentration of the first conductive dopant of the second region (112b) may be lower than the concentration of the first conductive dopant of the 1-1 conductive sub-semiconductor layer (113).

[0120] The thickness of the second region (112b) may be equal to or greater than the thickness of the first region (112a).

[0121] Additionally, the bunker layer (112) may further include a third region (112c).

[0122] The first region (112a) may be positioned between the second region (112b) and the third region (112c). That is, the third region (112c) may be a layer closer to the active layer (130) than the first region (112a) and the second region (112b).

[0123] The concentration of the first conductive dopant in the first region (112a) may be greater than the concentration of the first conductive dopant in the third region (112c). The concentration of the first conductive dopant in the third region (112c) may be the same as or similar to the concentration of the first conductive dopant in the second region (112b).

[0124] The third region (112c) is a region in which the first conductive dopant is doped at a low concentration, and may be a current spreading layer for improving current spreading by increasing resistance due to a low doping concentration.

[0125] The thickness of the third region (112c) may be smaller than the thicknesses of the first and second regions (112a, 112b). The thickness of the third region (112c) may be within 0.2 times the thickness of the first and second regions (112a, 112b).

[0126] Referring again to FIG. 3, FIG. 3 is a content profile showing the distribution of the content of each component (Ga, Al, In, P, Te, Si, Mg) according to depth from the surface of the second conductive semiconductor layer (120).

[0127] The above-described bunker layer (112) may correspond to the bunker (BK) in the profile of Fig. 3. The bunker (BK) may refer to a section in the content distribution profile where the content of the first material in the first conductive semiconductor layer (110) decreases and appears in a sunken shape (puddle shape).

[0128] The above bunker (BK) may be formed within 3 μm in an area corresponding to the active layer (130). The bunker (BK) may include first and second inclined surfaces (SL1, SL2) at both ends of which the content of the first material is variable.

[0129] The first inclined plane (SL1) may correspond to the slope of the content profile of the first material in the first variable section (CH1) of the bunker (BK), and the second inclined plane (SL2) may correspond to the slope of the content profile of the first material in the second variable section (CH2) of the bunker (BK). The second inclined plane (SL2) may be positioned closer to the active layer (130) region.

[0130] As shown in Fig. 3, the first variable section (CH1) is a region where the content of the first material increases with depth, and the slope at the first inclined plane (SL1) may have a positive value. The second variable section (CH2) is a region where the content of the first material decreases with depth, and the slope at the second inclined plane (SL2) may have a negative value.

[0131] The absolute value of the slope of the first inclined plane (SL1) and the second inclined plane (SL2) may be defined as a slope. In this case, the slope of the first inclined plane (SL1) may be different from the slope of the second inclined plane (SL2). For example, the slope of the second inclined plane (SL2) may be greater than the slope of the first inclined plane (SL1).

[0132] The length of the first inclined surface (SL1) may be different from the length of the second inclined surface (SL2). Here, the length of the first inclined surface (SL1) may be determined by the thickness of the first variable section (CH1) forming the first inclined surface (SL1) and the change in the content of the first material in the first variable section (CH1). Similarly, the length of the second inclined surface (SL2) may be determined by the thickness of the second variable section (CH2) forming the second inclined surface (SL2) and the change in the content of the first material in the second variable section (CH2).

[0133] For example, the length of the second inclined surface (SL2) may be longer than the length of the first inclined surface (SL1).

[0134] In the above bunker (BK), an imaginary dotted line (M) passing through the center of the content profile of the second material and the content profile of the first material can intersect with the content profile of the first material in the first variable section (CH1) and the second variable section (CH2), respectively.

[0135] Additionally, the difference (G1) between the content of the first material and the content of the third material in the bunker (BK) may be smaller than the difference (G2) between the content of the first material and the content of the second material.

[0136] Within 3 μm from the above bunker (BK), the content profile of the first material and the content profile of the second material may have at least two intersection points (CR1, CR2). The magnitude relationship between the content of the first material and the content of the second material may change before and after the intersection points (CR1, CR2).

[0137] The above two intersections (CR1, CR2) may be formed in the first-second conductive sub-semiconductor layer (111). In addition, the intersections (CR1, CR2) may be formed at a higher position than the bunker (BK).

[0138] The above-described light-emitting element (100) may be provided in a quantity of at least one to constitute a light-emitting device. The light-emitting device is a device including at least one light-emitting element (100), and may be a display panel, a display device, a lighting device, or the like. In particular, the above-described light-emitting element (100) may be one of the LEDs constituting a pixel (PX) of a display device, and may be applied as a RED LED, for example.

[0139] The light-emitting device (100) according to the present invention has the advantage of being able to improve the electrical characteristics of the light-emitting device (100) by enabling low resistance at high current even when the chip size is miniaturized.

[0140]

[0141] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art or having ordinary knowledge in the art that various modifications and changes to the present invention can be made without departing from the spirit and technical scope of the present invention as set forth in the claims to be described below.

[0142] Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the patent claims.

Claims

1. First challenge type semiconductor layer; A second conductive semiconductor layer disposed on top of the first conductive semiconductor layer; and A light emitting device comprising an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer, A light-emitting device including a bunker layer in which the first conductive semiconductor layer has a reduced content of the first material and a content profile of the first material according to the vertical depth is sunken.

2. In claim 1, The above bunker layer is a light-emitting element formed within 3um from the above active layer.

3. In claim 1, The above bunker layer is a light emitting element that forms a first variable section in which the content of the first material is variable and a second variable section spaced apart from the first variable section in which the content of the first material is variable.

4. In claim 3, A light emitting element in which the rate of change in the content of the first material according to the change in the distance from the active layer in the first variable section is different from the rate of change in the content of the first material according to the change in the distance from the active layer in the second variable section.

5. In claim 3, The above second variable section is a light emitting element closer to the active layer than the above first variable section.

6. In claim 3, A light emitting element in which the difference between the maximum and minimum values ​​of the content of the first material in the second variable section is greater than the difference between the maximum and minimum values ​​of the content of the first material in the first variable section.

7. In claim 1, The above bunker layer further includes a second material and a third material, The first material is Al, the second material is In, and the third material is Ga. A light emitting element in which the difference between the content of the first material and the content of the third material in the bunker layer is smaller than the difference between the content of the first material and the content of the second material.

8. In claim 7, A light emitting element in which the median value of the content of the first material and the content of the second material in the bunker layer is included in the first material content area in the first and second variable sections.

9. In claim 1, The above bunker layer further includes a second material, The first material is Al, the second material is In, A light emitting element in which at least two intersections are formed within 3 um from the bunker layer, where the magnitude relationship between the content of the first material and the content of the second material is different.

10. In claim 1, A light emitting device in which the content of the first material at the intersection is greater than the content of the first material in the bunker layer.

11. In claim 1, The above bunker layer is a light-emitting device including a first region and a second region having different concentrations of the first challenge-type dopant.

12. In claim 11, The first region is closer to the active layer than the second region, A light emitting device in which the concentration of the first conductive dopant in the first region is greater than the concentration of the first conductive dopant in the second region.

13. In claim 11, The above bunker layer further includes a third area, The first region is a light emitting element disposed between the second region and the third region.

14. In claim 13, A light emitting device in which the concentration of the first conductive dopant in the first region is greater than the concentration of the first conductive dopant in the third region.

15. In claim 13, A light emitting element in which the thickness of the third region is smaller than the thickness of the second region.

16. A light emitting device comprising a first conductive semiconductor layer; a second conductive semiconductor layer disposed on the first conductive semiconductor layer; and an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer. A light-emitting device including a bunker in which the content profile of the first material according to the vertical depth is formed in a depressed form by decreasing the content of the first material in the first conductive semiconductor layer, with the content profile of the first material according to the vertical depth from the surface of the second conductive semiconductor layer being lowered.

17. In claim 16, The bunker comprises first and second inclined surfaces having variable contents of the first material at both ends, A light emitting element in which the slope of the first inclined surface is different from the slope of the second inclined surface.

18. In claim 17, A light emitting element in which the length of the second inclined surface is longer than the length of the first inclined surface.

19. In claim 17, A light emitting element in which the first inclined surface is closer to the active layer than the second inclined surface.

20. In claim 16, The above bunker further comprises a second material, The first material is Al, the second material is In, A light emitting element in which the content profile of the first material and the content profile of the second material have at least two intersection points within 3 um from the bunker.

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