KR102564122B1 - Semiconductor device - Google Patents

Abstract

The embodiment includes a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, and a plurality of recesses extending from the second conductivity type semiconductor layer to the first conductivity type semiconductor layer through the active layer. A semiconductor structure comprising; a current diffusion layer disposed on the second conductivity type semiconductor layer and made of a material having an energy band gap smaller than that of the second conductivity type semiconductor layer; a first electrode layer contacting the first conductivity type semiconductor layer in the recess region; and a second electrode layer contacting the current diffusion layer, wherein the second conductivity type semiconductor layer includes a first region overlapping the recess in a vertical direction and a second region overlapping the recess in a vertical direction, A lower surface of the second conductivity type semiconductor layer is exposed in the first region, and the current diffusion layer provides a semiconductor device disposed on the second region.

Description

Semiconductor device {SEMICONDUCTOR DEVICE}

Embodiments relate to semiconductor devices, and more particularly, to semiconductor devices with improved light extraction efficiency.

Semiconductor devices including compounds such as GaN and AlGaN have many advantages, such as having a wide and easily adjustable band gap energy, and can be used in various ways such as light emitting devices, light receiving devices, and various diodes.

In particular, light emitting devices such as light emitting diodes or laser diodes using group 3-5 or group 2-6 compound semiconductor materials of semiconductors are developed in thin film growth technology and device materials to produce red, green, Various colors such as blue and ultraviolet can be realized, and white light with high efficiency can be realized by using fluorescent materials or combining colors. , safety, and environmental friendliness.

In addition, when light receiving devices such as photodetectors or solar cells are manufactured using group 3-5 or group 2-6 compound semiconductor materials, photocurrent is generated by absorbing light in various wavelength ranges through the development of device materials. By doing so, it is possible to use light in a wide range of wavelengths from gamma rays to radio wavelengths. In addition, it has the advantages of fast response speed, safety, environmental friendliness, and easy control of element materials, so that it can be easily used in power control or ultra-high frequency circuits or communication modules.

Accordingly, the semiconductor device can replace a transmission module of an optical communication means, a light emitting diode backlight that replaces a Cold Cathode Fluorescence Lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, and can replace a fluorescent lamp or an incandescent bulb. Applications are expanding to white light emitting diode lighting devices, automobile headlights and traffic lights, and sensors that detect gas or fire. In addition, applications of semiconductor devices can be expanded to high-frequency application circuits, other power control devices, and communication modules.

1 is a view showing a conventional light emitting device.

In the light emitting device 100, a light emitting structure 120 including a first conductivity type semiconductor layer 122, an active layer 124, and a second conductivity type semiconductor layer 126 is disposed on a substrate 110, and the first conductivity type semiconductor layer 120 is disposed. A first electrode 162 and a second electrode 166 are disposed on the type semiconductor layer 122 and the second conductivity type semiconductor layer 126, respectively.

In addition, the energy determined by the energy band inherent to the material constituting the active layer 124 when the electrons injected through the first conductivity type semiconductor layer 122 and the holes injected through the second conductivity type semiconductor layer 126 meet each other. emits light with Light emitted from the active layer 124 may vary depending on the composition of the material constituting the active layer, and may be blue light, ultraviolet (UV), or deep UV.

However, conventional light emitting devices have the following problems.

In the case of a light emitting device emitting light in the ultraviolet wavelength region, p-GaN may be used as the second conductive semiconductor layer 126 or p-GaN may be disposed on p-AlGaN for current spreading. At this time, since p-GaN has a high light absorbance in the UVC wavelength region, the light extraction efficiency of the light emitting device may decrease.

The embodiment is intended to improve the light extraction efficiency of the light emitting device.

The embodiment includes a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, and a plurality of recesses extending from the second conductivity type semiconductor layer to the first conductivity type semiconductor layer through the active layer. A semiconductor structure comprising; a current diffusion layer disposed on the second conductivity type semiconductor layer and made of a material having an energy band gap smaller than that of the second conductivity type semiconductor layer; a first electrode layer contacting the first conductivity type semiconductor layer in the recess region; and a second electrode layer contacting the current diffusion layer, wherein the second conductivity type semiconductor layer includes a first region overlapping the recess in a vertical direction and a second region overlapping the recess in a vertical direction, A lower surface of the second conductivity type semiconductor layer is exposed in the first region, and the current diffusion layer provides a semiconductor device disposed on the second region.

A thickness of the second conductivity type semiconductor layer in the first region may be smaller than a thickness of the second conductivity type semiconductor layer in the second region.

The active layer may emit light in the ultraviolet wavelength region.

The second conductivity type semiconductor layer is made of AlxGa(1-x)N doped with a second conductivity type dopant, and x may be 0.4 or more and 0.8 or less.

A thickness of the second conductivity type semiconductor layer in the first region may be 1/5 to 1/20 of a thickness of the second conductivity type semiconductor layer in the second region.

The composition ratio of Al in the current diffusion layer may be 40% or more.

A width of the lower surface of the second conductivity type semiconductor layer in the first region may be 2 micrometers to 5 micrometers.

The recess may further include a first insulating layer disposed to extend from a surface of the light emitting structure to a lower surface of the current diffusion layer in the recess, and the first insulating layer may be spaced apart from the second electrode layer.

The semiconductor device may further include a conductive reflective layer disposed surrounding the second electrode layer, and the reflective layer may make Schottky contact with the current diffusion layer between the first insulating layer and the second electrode layer.

The reflective layer extends from the first insulating layer on the lower surface of the second conductivity type semiconductor layer, and the end of the reflective layer is 1 micrometer away from the end of the first insulating layer on the lower surface of the second conductivity type semiconductor layer. to 2 micrometers apart.

The semiconductor device further includes a second insulating layer disposed under the first insulating layer and the reflective layer, wherein the second insulating layer is interposed between the first insulating layer and the first electrode layer in the recess. It can come into contact with a 1-conductivity semiconductor layer.

The second conductivity type semiconductor layer according to the embodiment forms a stepped structure having at least two thicknesses, and the thickness of the second conductivity type semiconductor layer may be formed to be relatively thin in a first region adjacent to the first electrode layer, which is an n-type electrode layer. there is. This structure can prevent an increase in light absorption in the ultraviolet wavelength region by GaN.

1 is a view showing a conventional light emitting device,
2 is a diagram showing an embodiment of a semiconductor device;
3A to 3C are diagrams showing detailed embodiments of area 'A' of FIG. 2;
4 is a diagram showing the light transmittance of AlGaN,
FIG. 5 is a view illustrating a package in which the semiconductor device of FIG. 2 is disposed.

Hereinafter, embodiments of the present invention that can specifically realize the above object will be described with reference to the accompanying drawings.

In the description of the embodiment according to the present invention, in the case of being described as being formed on "on or under" of each element, on or under (on or under) or under) includes both elements formed by directly contacting each other or by indirectly placing one or more other elements between the two elements. In addition, when expressed as "on or under", it may include the meaning of not only the upward direction but also the downward direction based on one element.

A semiconductor device according to an embodiment may include various electronic devices such as a light emitting device and a light receiving device, and both the light emitting device and the light receiving device may include a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer.

A semiconductor device according to this embodiment may be a light emitting device.

The light emitting device emits light by recombination of electrons and holes, and the wavelength of this light is determined by the energy band gap inherent in the material. Thus, emitted light may vary depending on the composition of the material.

When the light emitting structure includes AlGaN having a large Al composition ratio, it can emit light in the ultraviolet, especially deep ultraviolet wavelength region. Ultraviolet light may have a wavelength in the range of, for example, 10 nanometers to 400 nanometers, UV-A (near ultraviolet ray) may have a wavelength in the range of, for example, 320 nanometers to 400 nanometers, and UV-B ( Far ultraviolet rays) may have a wavelength ranging from 280 nanometers to 320 nanometers, and UV-C (deep ultraviolet rays) may have a wavelength ranging from 100 nanometers to 280 nanometers.

FIG. 2 is a diagram illustrating an exemplary embodiment of a semiconductor device, and FIGS. 3A to 3CS are diagrams illustrating exemplary embodiments of region 'A' of FIG. 2 in detail.

The semiconductor device according to the present embodiment includes a semiconductor structure 220 including a first conductivity type semiconductor layer 222, an active layer 224, and a second conductivity type semiconductor layer 226, and a first conductivity type semiconductor layer ( 222) and a second electrode layer 246 in contact with the second conductivity type semiconductor layer 226, and the thickness of the second conductivity type semiconductor layer 226 is the first electrode layer ( 242) may be thicker in the second region spaced apart from the first electrode layer 242 than in the first region adjacent thereto. The first region may be a region overlapping the recess in a vertical direction, and the second region may be a region not overlapping the recess in a vertical direction.

In the semiconductor device 200A, a plurality of recesses are formed in the light emitting structure 200, and the recesses are formed from the current diffusion layer 228 and the second conductivity type semiconductor layer 226 to the active layer 224 and the first Part of the conductive semiconductor layer 222 may be removed, and the first conductive semiconductor layer 222 may be exposed in an upper region of the recess of FIG. 2 .

A region in which a recess is formed may be referred to as a recess region, and a cross section of the recess region may be, for example, circular, polygonal, or elliptical, but is not necessarily limited thereto. The number of recesses may be freely adjusted in consideration of the size, current density, and light output of the semiconductor device 200A.

The first conductivity type semiconductor layer 222 may be implemented with a compound semiconductor such as group III-IV or group II-V, and may be doped with a first conductivity type dopant. The first conductivity-type semiconductor layer 222 is AlGaN, a semiconductor material having a composition formula of Al _x In _y Ga _(1-xy) N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) , GaN, InAlGaN, AlGaAs, GaP, GaAs, GaAsP, can be grown as any one or more of AlGaInP.

In particular, when the first conductivity type semiconductor layer 222 is Al _x Ga _(1-x) N (0.4≤x≤0.8), the active layer may emit light in a UVB or UVC wavelength region.

When the first conductivity-type semiconductor layer 222 is an n-type semiconductor layer, the first conductivity-type dopant may include an n-type dopant such as Si, Ge, Sn, Se, or Te. The first conductivity type semiconductor layer 222 may be grown as a single layer or multiple layers, but is not limited thereto.

The active layer 224 may include any one of a single well structure, a multi well structure, a single quantum well structure, a multi quantum well (MQW) structure, a quantum dot structure, or a quantum wire structure.

The active layer 224 is a well layer and a barrier layer, for example, AlGaN/AlGaN, InGaN/GaN, InGaN/InGaN, AlGaN/GaN, InAlGaN/GaN, GaAs (InGaAs), using compound semiconductor materials of group III-IV elements. , / AlGaAs, GaP (InGaP) / AlGaP may be formed in a pair structure of one or more, but is not limited thereto. The well layer may be formed of a material having an energy band gap smaller than that of the barrier layer.

When the second conductivity type semiconductor layer 226 is AlxGa(1-x)N (0.4≤x≤0.8), the active layer may emit light in a UVB or UVC wavelength region.

A second conductivity type semiconductor layer 226 is disposed under the active layer 224. The second conductivity type semiconductor layer 226 may be formed of a semiconductor compound, and the raw material is, for example, gallium (Ga) or ammonia. (NH ₃ ). The second conductivity type semiconductor layer 226 may be implemented with a compound semiconductor such as group III-IV or group II-V, and may be doped with a second conductivity type dopant. The second conductive semiconductor layer 226 is, for example, a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0≤x≤1, 0≤y≤1, 0≤x+y≤1) , AlGaN, GaN, AlInN, AlGaAs, GaP, GaAs, GaAsP, may be formed of any one or more of AlGaInP.

When the second conductivity type semiconductor layer 226 is a p-type semiconductor layer, the second conductivity type dopant may be a p-type dopant such as Mg, Zn, Ca, Sr, or Ba. The second conductivity type semiconductor layer 226 may be formed as a single layer or multiple layers, but is not limited thereto.

In the case of a light emitting device that emits light in the ultraviolet wavelength region, particularly in the UVC region, the second conductivity type semiconductor layer 226 may be made of AlxGa(1-x)N based, and when x>0.4, that is, the composition ratio of aluminum When is 40% or more, absorption of light in the ultraviolet wavelength region, particularly in the UVC region, by the second conductivity type semiconductor layer can be effectively prevented.

When the second conductive semiconductor layer 226 is made of AlGaN, hole injection may not be smooth due to low electrical conductivity of AlGaN, and ohmic contact with a metal used as an electrode material may not be relatively smooth. In this case, the aforementioned problems may be solved by disposing a GaN-based material having relatively excellent electrical conductivity and a smaller energy band gap under the second conductivity type semiconductor layer 226 . In FIG. 2 , the GaN-based current diffusion layer 228 may be disposed on the lower surface of the second conductivity type semiconductor layer 226 .

An upper surface of the first conductivity-type semiconductor layer 222 may have concavities and convexities, and when it has a height of 300 nanometers to 800 nanometers and an average height of 500 nanometers, a light emitting element in the ultraviolet region, particularly the UVC region ( 200A) can effectively improve the light extraction efficiency. The width may increase from the first conductivity-type semiconductor layer 222 toward the active layer 224, the second conductivity-type semiconductor layer 226, and the current diffusion layer 228. In the mesa etching process, the light emitting structure 220 This is because the width of the lower structure can be etched wider.

In FIG. 2 , each recess is provided with a step difference, and the width of the recess in the lower region may be wider than that of the recess in the upper region. Due to the stepped structure of the recess, the thickness of the second conductivity type semiconductor layer 226 may be non-uniform.

3A to 3C, the first conductivity type semiconductor layer 222 may be AlGaN doped with an n-type dopant, the second conductivity type semiconductor layer 226 may be AlGaN doped with a p-type dopant, and the current spreading layer (228) may be GaN and may be doped with a p-type dopant.

Since the first conductivity type semiconductor layer 222 made of n-AlGaN has low electrical conductivity, the flow of electrons is concentrated in a region adjacent to the first ohmic layer 242 in the first conductivity type semiconductor layer 222, and thus Combination of electrons and current may be concentrated in the active layer 224 adjacent to the recess.

In addition, when the second conductivity-type semiconductor layer 226 is p-AlGaN, the second electrode layer 246 and ohmic characteristics are not good, so GaN having excellent ohmic characteristics with the second electrode layer 246 is used as the current diffusion layer 228 can be used as

The current diffusion layer 228 has the above-described ohmic and current diffusion characteristics, but has a high light absorption rate in the UV wavelength region.

Therefore, in the light emitting device according to the embodiment, in order to reduce UV absorption in the current diffusion layer 228 made of GaN in the region adjacent to the active layer 224 in the region where the combination of electrons and current is concentrated, the region adjacent to the recess. In the current diffusion layer 228 was removed.

Referring to FIG. 3A , a portion of the second conductivity-type semiconductor layer 226 vertically overlapping with the recess may be referred to as a first region, and a portion adjacent to the first region and not overlapping with the recess in the vertical direction is excluded. It may be referred to as two regions, the first region may be adjacent to the first electrode layer 242 and the second region may be adjacent to the second electrode layer 246, and the second conductive semiconductor layer 226 may be formed in the first region. The thickness t22 may be smaller than the thickness t21 of the second conductivity type semiconductor layer 226 in the second region.

In detail, among the first regions of the second conductivity-type semiconductor layer 226 having a thickness t22, the width w1 of the lower surface parallel to the active layer 224 in the horizontal direction may be 2 micrometers to 5 micrometers. there is. Here, if the width (w1) is narrower than 2 micrometers, absorption of light emitted from the active layer 224 may increase, and if it is wider than 5 micrometers, the active layer 224 in the second conductivity type semiconductor layer 226 Holes supplied in the direction may decrease. The width w1 may be a part of the second conductivity type semiconductor layer 226 constituting the first region.

The thickness t22 of the second conductivity type semiconductor layer 226 in the first region may be, for example, 50 nanometers or less, and the thickness t21 of the second conductivity type semiconductor layer 226 in the second region It may be 1/5 to 1/20.

If the above-described thickness t22 is less than 1/20 of the thickness t21, the volume of the second conductive semiconductor layer 226 in the first region is too small and the resistance is high, so that the direction of the active layer 224 in the first region The supply of holes to the may not be smooth.

If the aforementioned thickness t22 is greater than 1/5 of the thickness t21, UV may be partially absorbed by the second conductivity type semiconductor layer 226 in the first region. In the embodiment of FIG. 3B, the first region It is different from the embodiment of FIG. 3A in that the current blocking layer 228 is completely removed in . Also, a width w2 of a region where the current diffusion layer 228 is not disposed on the lower surface of the second conductive semiconductor layer 226 may be 2 micrometers to 5 micrometers.

The embodiment of FIG. 3C is similar to the embodiment of FIG. 3A , but has a difference in that the reflective layer 250 extends to the lower portion of the second conductivity type semiconductor layer 226 in the first region. UV generation is concentrated in the active layer 224 in the first region. At this time, the reflective layer 250 is extended and disposed in the first region to reflect light generated in the active layer 224 and traveling in the direction of the first region. .

In consideration of the process margin, the reflective layer 250 may be disposed at a distance d3 from the end of the first insulating layer 231 on the lower surface of the second conductivity type semiconductor layer 226, and the distance d3 may be between 1 micrometer and 2 micrometers. If the distance d3 is less than 1 micrometer, it may be difficult to secure a margin in the process of forming the reflective layer 250, and if it is greater than 2 micrometers, the light generated from the active layer 224 and propagating downward will The non-reflecting area may increase.

A reflective layer 250 may be disposed on the current diffusion layer 228 surrounding the second electrode layer 246 and below the second region of the second conductivity type semiconductor layer 226. It may act as a capping layer supporting the second electrode layer 246 on the surface.

The reflective layer 250 may be made of a conductive material, for example, may be made of metal, and specifically composed of chromium (Cr), aluminum (Al), titanium (Ti), gold (Au), and nickel (Ni). It may be made of at least one material selected from the group and alloys thereof, but is not limited thereto, and may reflect light emitted from the active layer 224 and proceeding to the lower region to proceed to the upper region again. When the reflective layer 250 has a multilayer structure, aluminum (Al) having the highest reflectance may be disposed on the top of FIG. 2 closest to the active layer 224 .

A first insulating layer 231 is disposed spaced apart from the first electrode layer 242 by a predetermined distance, and the first insulating layer 231 extends from the exposed surface of the first conductivity type semiconductor layer 22 to the side of the recess region. It may extend to the surface of the current spreading layer 228. Further, the first insulating layer 231 may be disposed on the exposed lower surface of the current diffusion layer 228 and spaced apart from both ends of the second electrode layer 246 by a predetermined distance.

The first insulating layer 231, the second insulating layer 232 and the passivation layer 290, which will be described later, may be made of an insulating material, for example, aluminum oxide or aluminum nitride may be used, and in detail, SiO2 or SiN. this can be used

The thickness t11 of the second electrode layer 246 may be the same as the thickness of the first electrode layer 242 and may be smaller than the thickness t12 of the first insulating layer 231 . The thickness t12 of the second insulating layer 232 may be 4,000 angstroms to 10,000 angstroms, for example, 8,000 angstroms.

If the thickness t12 of the second insulating layer 232 is smaller than the above range, reliability for electrical separation such as the second electrode layer 246 and the reflective layer 250 may decrease, and if it is thicker than the above range Defects such as cracks or voids may occur due to pressure applied when the support substrate 280 is bonded through the bonding layer 270 , and reliability may deteriorate.

Further, in a region between the second electrode layer 246 and the first insulating layer 231, the reflective layer 250 makes a Schottky contact with the second conductive semiconductor layer 226 or the current diffusion layer 228. can do.

The distance d1 of the above-mentioned Schottky contact area may be 1 micrometer to 2 micrometers, and the above-described width can be secured through a self-align process, and when forming the reflective layer 250 Reliability can be improved because the step coverage characteristics are good.

In one area of the light emitting structure 220, the first insulating layer 231 is extended and disposed and open in a partial area, and the second electrode 266 is disposed on the open first insulating layer 231, and the second The electrode 266 may be electrically connected to the lower reflective layer 250 .

The passivation layer 290 is disposed on the top and side surfaces of the light emitting structure 220 , and the first insulating layer 231 and the passivation layer 290 may contact each other in an area adjacent to the second electrode 266 .

A second insulating layer 232 is disposed below the first insulating layer 231 and the reflective layer 250. The lower surface may contact the first electrode layer 242 . In addition, the second insulating layer 232 contacts the edge of the first electrode layer 242 and exposes the central region of the first electrode layer 242, and the lower reflective layer (described later) on the exposed first electrode layer 242 ( 275) can be contacted.

The lower reflective layer 275 and the bonding layer 270 may be disposed along the lower surface of the light emitting structure 220 and the shape of the recess. The lower reflective layer 275 may upwardly reflect UV light traveling to a region where the aforementioned reflective layer 250 is not formed, that is, to a lower portion of the recess.

The lower reflective layer 275 may be made of a material having excellent reflectivity, for example, aluminum (Al), and should be provided with a thickness of, for example, 500 angstroms or more in the ultraviolet wavelength region to secure a light reflectance of 80% or more. can

The bonding layer 270 includes a region in which the lower reflective layer 275 is bonded to the lower support substrate 280 by diffusion bonding or eutectic bonding including a region in which Ni, Sn, Au, etc. are mixed. can be an area.

A diffusion barrier layer (not shown) may be disposed between the lower reflective layer 275 and the bonding layer 270. The diffusion barrier layer may have, for example, a multilayer structure of titanium/nickel/titanium/nickel. .

The support substrate 280 may be made of a conductive material, and may be formed of, for example, a metal or semiconductor material. The material of the substrate 360 may be a metal having excellent electrical conductivity or thermal conductivity, and since it should be able to sufficiently dissipate heat generated during operation of the light emitting device, it may be formed of a material having high thermal conductivity. For example, it may be made of a material selected from the group consisting of silicon (Si), molybdenum (Mo), silicon (Si), tungsten (W), copper (Cu), and aluminum (Al) or an alloy thereof, In addition, gold (Au), copper alloy (Cu Alloy), nickel (Ni), copper-tungsten (Cu-W), carrier wafer (eg GaN, Si, Ge, GaAs, ZnO, SiGe, SiC, SiGe, Ga ₂ O ₃ , etc.) and the like may optionally be included.

4 is a diagram showing light transmittance of AlGaN. When the composition ratio of aluminum increases, the light transmittance increases. In particular, since the light transmittance increases as the wavelength becomes shorter, light absorption may increase.

In the light emitting device according to the embodiment, the second conductivity type semiconductor layer 226 has a stepped structure having at least two thicknesses, and the second conductivity type semiconductor layer 226 is formed in a first region adjacent to the first electrode layer, which is an n-type electrode layer. The thickness of may be formed relatively thin. This structure reduces the thickness of the second conductivity-type semiconductor layer 226 made of AlGaN in the area adjacent to the first electrode layer 242 and removes the storage blocking layer 228 to prevent the hole injection characteristic from deteriorating. , it is possible to prevent an increase in light absorption in the ultraviolet wavelength region by GaN.

FIG. 5 is a view illustrating a package in which the semiconductor device of FIG. 2 is disposed.

The light emitting device package 300 according to the embodiment includes a package body 310, a first electrode portion 321, a second electrode portion 322, and a light emitting device 200A.

The package body 310 may be made of an insulating material having a cavity, and may include, for example, polypthalamide (PPA) resin or a silicon-based material.

The electrode unit 321 and the second electrode unit 322 are disposed on the package body 310, respectively, and some may be disposed on the bottom surface of the cavity.

The light emitting element 200A may be the light emitting element described above, and may be disposed on the first electrode part 321 and electrically connected to the second electrode part 322 through the wire 330 .

The periphery of the light emitting element 200 and the wire 330 may be filled with air. In the case of a light emitting device that emits ultraviolet rays, if a molding portion made of a silicon-based material is disposed in a region around the light emitting device, defects such as cracks may occur in the molding portion due to energy corresponding to the wavelength of the ultraviolet rays, and thus reliability may be deteriorated.

A phosphor (not shown) may be included around the light emitting element 200A. The phosphor may be YAG-based phosphor, nitride-based phosphor, silicate, or a mixture thereof, but is not limited thereto.

A groove is formed on the top of the package body 310 and a cover 370 is disposed on the groove. The cover 370 may be made of a light-transmitting material such as glass, and the package body 310 and the The cover 370 may be coupled, and the adhesive 375 may be, for example, a silicon-based adhesive.

In addition to the shape of the package of FIG. 5 , the semiconductor device may be flip-bonded and used as a package.

The light emitting device described above is composed of a light emitting device package and can be used as a light source of a lighting system, for example, a light source of an image display device or a light source of a lighting device. In particular, a light emitting device that emits light in the ultraviolet wavelength region may be used in a sterilization device or medical device such as a water purification device or an air purifier.

When used as a backlight unit of an image display device, it can be used as an edge-type backlight unit or a direct-type backlight unit, and when used as a light source for a lighting device, it can be used as a lamp or bulb type, and can also be used as a light source for mobile terminals. may be

The light emitting device includes a laser diode in addition to the above-described light emitting diode, and the structure of the light emitting device according to the embodiment may be applied to a laser diode and other semiconductor devices.

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

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

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

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

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

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

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

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

100, 200A: light emitting element 110: substrate
122, 222: first conductivity type semiconductor layer 124, 224: active layer
126, 226: second conductivity type semiconductor layer 162: first electrode
166, 266: second electrode 228: current diffusion layer
231: first insulating layer 232: second insulating layer
242: first electrode layer 246: second electrode layer
260: reflective layer 265: lower reflective layer
270: bonding layer 280: support substrate
290: passivation layer 300: light emitting device package

Claims (10)

A semiconductor including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer, and including a plurality of recesses extending from the second conductivity type semiconductor layer to the first conductivity type semiconductor layer through the active layer structure;
a current diffusion layer disposed on the second conductivity type semiconductor layer and made of a material having an energy band gap smaller than that of the second conductivity type semiconductor layer;
a first electrode layer contacting the first conductivity type semiconductor layer within the recess;
a second electrode layer in contact with the current spreading layer; and
A reflective layer disposed surrounding the second electrode layer; includes,
The second conductivity type semiconductor layer includes a first region overlapping the recess in a vertical direction and a second region overlapping the recess in a vertical direction, and the second conductivity type semiconductor layer is formed in the first region. the lower surface is exposed,
The current diffusion layer is disposed on the second region,
The first conductivity-type semiconductor layer is made of AlxGa(1-x)N, and x is 0.4 or more and 0.8 or less. According to claim 1,
The active layer is a semiconductor device that emits light in the UVB or UVC wavelength region. According to claim 1,
The semiconductor device of claim 1 , wherein a thickness of the second conductivity type semiconductor layer in the first region is 1/5 to 1/20 of a thickness of the second conductivity type semiconductor layer in the second region. delete According to claim 1,
A width of the second conductivity-type semiconductor layer in the first region in a horizontal direction is 2 micrometers to 5 micrometers. delete delete delete delete delete

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