CN109148663B - Light emitting diode and method for manufacturing the same - Google Patents
Light emitting diode and method for manufacturing the same Download PDFInfo
- Publication number
- CN109148663B CN109148663B CN201810987785.4A CN201810987785A CN109148663B CN 109148663 B CN109148663 B CN 109148663B CN 201810987785 A CN201810987785 A CN 201810987785A CN 109148663 B CN109148663 B CN 109148663B
- Authority
- CN
- China
- Prior art keywords
- layer
- type semiconductor
- type
- pad electrode
- semiconductor layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 15
- 238000000034 method Methods 0.000 title claims description 15
- 239000004065 semiconductor Substances 0.000 claims abstract description 80
- 229910052751 metal Inorganic materials 0.000 claims abstract description 40
- 239000002184 metal Substances 0.000 claims abstract description 40
- 239000000758 substrate Substances 0.000 claims abstract description 12
- 230000000903 blocking effect Effects 0.000 claims description 17
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 16
- 229910052782 aluminium Inorganic materials 0.000 claims description 16
- 239000011651 chromium Substances 0.000 claims description 16
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 15
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 15
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 14
- 229910052804 chromium Inorganic materials 0.000 claims description 14
- 229910052709 silver Inorganic materials 0.000 claims description 14
- 239000004332 silver Substances 0.000 claims description 14
- 239000010931 gold Substances 0.000 claims description 9
- 239000010936 titanium Substances 0.000 claims description 8
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 7
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 7
- 229910052737 gold Inorganic materials 0.000 claims description 7
- 229910052759 nickel Inorganic materials 0.000 claims description 7
- 229910052697 platinum Inorganic materials 0.000 claims description 7
- 229910052719 titanium Inorganic materials 0.000 claims description 7
- 238000002161 passivation Methods 0.000 abstract description 11
- 238000000605 extraction Methods 0.000 abstract description 9
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 10
- 229910002601 GaN Inorganic materials 0.000 description 7
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical class [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 description 6
- 239000000126 substance Substances 0.000 description 5
- 239000010408 film Substances 0.000 description 3
- 230000031700 light absorption Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000000231 atomic layer deposition Methods 0.000 description 2
- 238000005229 chemical vapour deposition Methods 0.000 description 2
- 239000002019 doping agent Substances 0.000 description 2
- 238000002248 hydride vapour-phase epitaxy Methods 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 2
- 229910005540 GaP Inorganic materials 0.000 description 1
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- JNDMLEXHDPKVFC-UHFFFAOYSA-N aluminum;oxygen(2-);yttrium(3+) Chemical compound [O-2].[O-2].[O-2].[Al+3].[Y+3] JNDMLEXHDPKVFC-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005566 electron beam evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 238000001755 magnetron sputter deposition Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- JBQYATWDVHIOAR-UHFFFAOYSA-N tellanylidenegermanium Chemical compound [Te]=[Ge] JBQYATWDVHIOAR-UHFFFAOYSA-N 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
- 229910019901 yttrium aluminum garnet Inorganic materials 0.000 description 1
- XLOMVQKBTHCTTD-UHFFFAOYSA-N zinc oxide Inorganic materials [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/36—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes
- H01L33/40—Materials therefor
- H01L33/405—Reflective materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/36—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/36—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes
- H01L33/38—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the electrodes with a particular shape
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/44—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the coatings, e.g. passivation layer or anti-reflective coating
- H01L33/46—Reflective coating, e.g. dielectric Bragg reflector
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Led Devices (AREA)
Abstract
The invention relates to a light emitting diode and a manufacturing method thereof. The semiconductor device comprises a substrate, an N-type semiconductor layer, an active layer and a P-type semiconductor layer which are sequentially arranged from bottom to top, wherein the areas of the active layer and the P-type semiconductor layer are smaller than that of the N-type semiconductor layer so as to expose part of the N-type semiconductor layer; the N-type pad electrode, the P-type pad electrode and the finger electrode respectively comprise an ohmic contact layer, a lower reflecting layer, a stress relieving layer, a conductive metal layer and an upper reflecting layer which are sequentially arranged from bottom to top. The invention prevents the light totally reflected by the passivation layer from being absorbed by the metal electrode through the upper reflection layer, thereby improving the external light extraction efficiency.
Description
Technical Field
The present invention relates to a light emitting diode and a method for manufacturing the same, and more particularly, to a light emitting diode including a reflective layer for improving light extraction efficiency by reducing light absorption of a pad electrode and a finger electrode, and a method for manufacturing the same.
Background
When the semiconductor light emitting element is connected to a forward voltage, holes in the P-type semiconductor layer are recombined with electrons in the N-type semiconductor layer, and light having a wavelength with a corresponding band gap width is emitted. Gallium nitride series semiconductor (Al)xInyGa1-x-yN, x is 0 to 1, y is 0 to 1, and x + y is 0 to 1) can emit light of various wavelengths by changing the composition ratio of three elements of Al, In and Ga, and thus the material is a light-emitting element material which is favored.
The P-type semiconductor layer constituting the gallium nitride-based semiconductor light-emitting device has a problem of an excessively large resistance due to a small carrier mobility. When a current is injected into the P-type gallium nitride semiconductor layer having a large resistance, electric charges are not diffused throughout the semiconductor layer but are concentrated in a path having a small resistance, and thus, a phenomenon of uneven light emission due to current crowding occurs. This phenomenon is one of the major problems of decreasing the luminance of the element.
Therefore, in order to diffuse the current to the entire P-type semiconductor layer, a transparent electrode layer is formed on the P-type semiconductor layer. Another way to spread the current throughout the P-type semiconductor layer is to form a finger electrode extending from the pad electrode to prevent the current from concentrating around the bond site connected to the wire.
Since both the pad electrode and the finger electrode are made of a highly conductive metal, and the electrode made of a metal material generally used is relatively thick, one of the factors that light absorption causes a decrease in light extraction efficiency is caused.
Disclosure of Invention
The invention aims to provide a light emitting diode and a manufacturing method thereof, which prevent light totally reflected by a passivation layer from being absorbed by a metal electrode through an upper reflection layer, thereby improving external light extraction efficiency.
In order to achieve the purpose, the technical scheme of the invention is as follows: a light emitting diode comprises a substrate, an N-type semiconductor layer, an active layer and a P-type semiconductor layer which are sequentially arranged from bottom to top, wherein the areas of the active layer and the P-type semiconductor layer are smaller than that of the N-type semiconductor layer so as to expose part of the N-type semiconductor layer; the N-type pad electrode, the P-type pad electrode and the finger electrode respectively comprise an ohmic contact layer, a lower reflecting layer, a stress relieving layer, a conductive metal layer and an upper reflecting layer which are sequentially arranged from bottom to top.
In an embodiment of the present invention, the ohmic contact layer is formed of chromium, the lower reflective layer is formed of aluminum or silver, the stress relaxation layer is formed of nickel, titanium, or chromium, and the conductive metal layer is formed of platinum or gold.
In an embodiment of the present invention, the upper reflective layer is formed of aluminum, silver, or DBR.
In an embodiment of the invention, a transparent electrode layer is further disposed between the P-type semiconductor layer and the P-type pad electrode.
In an embodiment of the invention, a current blocking layer is further disposed in a partial region between the P-type semiconductor layer and the transparent electrode layer, and the current blocking layer is located right below the P-type pad electrode.
The invention also provides a manufacturing method based on the light-emitting diode, which comprises the following steps of firstly, forming an ohmic contact layer on the P-type semiconductor layer; then, forming a lower reflection layer on the ohmic contact layer; then, forming a stress relaxation layer on the lower reflection layer; then, forming a conductive metal layer on the stress relaxation layer, and finally forming an upper reflection layer on the conductive metal layer; in the step of forming the upper reflective layer, the upper reflective layer is formed on a partial region of the conductive metal layer of the N-type pad electrode and the P-type pad electrode and on the entire conductive metal layer of the finger electrode.
In an embodiment of the present invention, the ohmic contact layer is formed of chromium, the lower reflective layer is formed of aluminum or silver, the stress relaxation layer is formed of nickel, titanium, or chromium, and the conductive metal layer is formed of platinum or gold.
In an embodiment of the present invention, in the process of forming the upper reflective layer, the upper reflective layer is formed on the conductive metal layers of the N-type and P-type pad electrodes and the finger electrode, and the upper reflective layer is removed from a partial region of the N-type and P-type pad electrodes.
In an embodiment of the present invention, the upper reflective layer is formed of aluminum, silver, or DBR.
In an embodiment of the present invention, a process of forming a current blocking layer on a partial region of the P-type semiconductor layer and a process of forming a transparent conductive layer on the current blocking layer and the P-type semiconductor layer are further included, and a P-type pad electrode is formed right above the region where the current blocking layer is formed.
Compared with the prior art, the invention has the following beneficial effects: the N-type pad electrode, the P-type pad electrode and the finger electrode comprise an ohmic contact layer, a lower reflecting layer, a stress relieving layer, a conductive metal layer and an upper reflecting layer. The ohmic contact layer enables the electrode structure to form ohmic contact with the P-type semiconductor layer or the transparent conducting layer, so that power is supplied to the P-type semiconductor layer more effectively. The lower reflective layer prevents light emitted from the active layer from being absorbed by the conductive metal layers of the N-type pad electrode, the P-type pad electrode, and the finger electrode. The stress relaxation layer is bonded to the lower reflection layer and the conductive metal layer. The conductive metal layer formed on the stress relaxation layer is used for electrifying the bonding wire. The upper reflective layer prevents light reflected by a passivation layer formed on the light emitting diode structure from being absorbed by the conductive metal layer. Therefore, the light emitting diode provided by the embodiment of the invention is easy to diffuse current, and the light emitting efficiency of the light emitting diode can be improved due to less light absorption.
Drawings
Fig. 1 is a plan view of a light emitting diode according to an embodiment of the invention.
Fig. 2 is a cross-sectional view of the led shown in fig. 1 cut along line a-a' and shown.
Fig. 3 is a cross-sectional view of the led shown in fig. 1 cut away along line B-B' to show the led.
Fig. 4 is a cross-sectional view of an electrode layer of a light emitting diode according to an embodiment of the invention.
In the figure, the position of the upper end of the main shaft,
10: substrate 20: luminescent layer
21: n-type semiconductor layer 23: active layer
25: p-type semiconductor layer 30: electrode layer
31: p-type pad electrode 33: p-type finger electrode
35: n-type pad electrode 37: n-type finger electrode
40. 40a, 40 b: upper reflective layer 51: transparent electrode layer
53: current blocking layer 60: passivation layer
71: ohmic contact layer 73: lower reflective layer
75: stress relaxation layer 77: a conductive metal layer.
Detailed Description
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is not intended to limit the invention to the particular forms shown, but, on the contrary, the intention is to cover all modifications, equivalents, alternatives, and equivalents falling within the spirit and scope of the invention as defined by the appended claims.
When an element such as a layer, a section, or a substrate is referred to as being present "on" another constituent element, it is to be understood that the element may be present directly on the other element or may be present as an intermediate element between the element and the other element.
Although the terms of level 1 and level 2 may be used to describe various elements, components, sections, layers and/or regions, it should be understood that these elements, components, sections, layers and/or regions are not limited to these terms.
Preferred embodiments of the present invention will be described in detail with reference to the following drawings. In the following drawings, the same reference numerals are used for the same components, and the description of the same components will not be repeated.
The invention provides a light-emitting diode, which comprises a substrate, an N-type semiconductor layer, an active layer and a P-type semiconductor layer which are sequentially arranged from bottom to top, wherein the areas of the active layer and the P-type semiconductor layer are smaller than that of the N-type semiconductor layer so as to expose part of the N-type semiconductor layer; the N-type pad electrode, the P-type pad electrode and the finger electrode respectively comprise an ohmic contact layer, a lower reflecting layer, a stress relieving layer, a conductive metal layer and an upper reflecting layer which are sequentially arranged from bottom to top.
The ohmic contact layer is formed of chromium, the lower reflection layer is formed of aluminum or silver, the stress relaxation layer is formed of nickel, titanium or chromium, and the conductive metal layer is formed of platinum or gold. The upper reflective layer is formed of aluminum, silver, or DBR.
And a transparent electrode layer is also arranged between the P-type semiconductor layer and the P-type pad electrode.
And a current blocking layer is also arranged in a partial area between the P-type semiconductor layer and the transparent electrode layer and is positioned right below the P-type welding disc electrode.
The invention also provides a manufacturing method based on the light-emitting diode, which comprises the following steps of firstly, forming an ohmic contact layer on the P-type semiconductor layer; then, forming a lower reflection layer on the ohmic contact layer; then, forming a stress relaxation layer on the lower reflection layer; then, forming a conductive metal layer on the stress relaxation layer, and finally forming an upper reflection layer on the conductive metal layer; in the step of forming the upper reflective layer, the upper reflective layer is formed on a partial region of the conductive metal layer of the N-type pad electrode and the P-type pad electrode and on the entire conductive metal layer of the finger electrode.
The ohmic contact layer is formed of chromium, the lower reflection layer is formed of aluminum or silver, the stress relaxation layer is formed of nickel, titanium or chromium, and the conductive metal layer is formed of platinum or gold. The upper reflective layer is formed of aluminum, silver, or DBR.
In the above method for manufacturing a light emitting diode, in the process of forming the upper reflective layer, the upper reflective layer is formed on the conductive metal layers of the N-type and P-type pad electrodes and the finger electrode, and the upper reflective layer on the partial regions of the N-type and P-type pad electrodes is removed.
The method for manufacturing a light emitting diode further includes a step of forming a current blocking layer on a partial region of the P-type semiconductor layer, and a step of forming a transparent conductive layer on the current blocking layer and the P-type semiconductor layer, and forming a P-type pad electrode directly above the region where the current blocking layer is formed.
The following are specific examples of the present invention.
Fig. 1 is a plan view of a light emitting diode according to an embodiment of the invention.
Referring to fig. 1, a light emitting diode according to an embodiment of the present invention includes a light emitting layer (20) including an N-type semiconductor layer, an active layer, and a P-type semiconductor, a P-type pad electrode (31) electrically connected to the P-type semiconductor, a P-type finger electrode (33) extending from the P-type pad electrode, an N-type pad electrode (35) electrically connected to the N-type semiconductor layer, and an N-type finger electrode (37) extending from the N-type pad electrode (35). The P-type finger electrode (33) extends from the P-type pad electrode (31) to the N-type pad electrode (35) on the P-type semiconductor layer.
The N-type finger electrode (37) is formed on the N-type semiconductor layer, and extends from the N-type pad electrode (35) to surround the P-type finger electrode (33). It is thus possible to efficiently conduct the current to the entire light-emitting layer (20).
Fig. 2 is a cross-sectional view of the led shown in fig. 1 cut along line a-a' and shown. Fig. 3 is a cross-sectional view of the led shown in fig. 1 cut away along line B-B' to show the led.
Referring to fig. 2, a light emitting diode according to an embodiment of the present invention includes a substrate (10), a light emitting layer (20) formed on the substrate (10) and including an N-type semiconductor layer (21), an active layer (23), and a P-type semiconductor layer (25), an electrode layer (30) including a P-type pad electrode (31) formed on the light emitting layer (20) and electrically connected to the P-type semiconductor layer (25), a P-type finger electrode (33) extending from the P-type pad electrode (31), an N-type pad electrode (35) electrically connected to the N-type semiconductor layer, an N-type finger electrode (37) extending from the N-type pad electrode (35), and a passivation layer (60).
Any substance that is known to be usable as a GaN LED substrate can be used as the substrate (10) without limitation. The semiconductor material generally used for growing gallium nitride may be any one of SiC, Si, GaN, ZnO, GaAs, GaP, LiAl2O3, BN and AlN, but is not limited thereto. The substrate (10) may have a concave-convex pattern so as to reflect light formed and emitted from the active layer (23) by growing a high-quality gallium nitride light emitting layer (20), thereby improving light extraction efficiency.
The gallium nitride light-emitting structure is formed on the substrate (10). First, an active layer (23) is formed on an N-type semiconductor layer (21). A P-type semiconductor layer (25) is further formed on the active layer (23). The P-type semiconductor layer (25) and the active layer (23) are partially etched to expose the N-type semiconductor layer (21).
The light-emitting layer (20) may be AlxInyGa1-x-yN (x is more than or equal to 0 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 1, and x + y is more than or equal to 0 and less than or equal to 1). The N-type semiconductor layer (21) may include an N-type dopant of a type such as silicon (Si), germanium (Ge), tin (Sn), and the P-type semiconductor may include a P-type dopant of a type such as magnesium (Mg), zinc (Zn), or cadmium (Cd). The active layer (23) may have a single quantum well structure or a multiple quantum well structure. The active layer (23) of the multiple quantum well structure may be a structure in which semiconductor layers having a large band gap and semiconductor layers having a small band gap are alternately stacked.
The N-type semiconductor layer (21), the active layer (23), and the P-type semiconductor layer (25) may be formed by Chemical Vapor Deposition (CVD), Hydride Vapor Phase Epitaxy (HVPE), Atomic layer deposition (Atomic layer deposition), or other well-known growth methods.
A transparent conductive layer (51) can be selectively formed on the P-type semiconductor layer (25). The transparent conductive layer (51) can be formed as a very thin Ni/Au thin film or a conductive metal oxide thin film. The transparent conductive layer (51) can diffuse a current to the P-type semiconductor layer (25) having a low hole density.
When the transparent conductive layer (51) is formed, a current blocking layer (53) can be formed in a partial region on the P-type semiconductor layer (25). The current blocking layer (53) is formed on the P-type pad electrode (31) and prevents current from flowing from below the P-type pad electrode to the active region. Then, the current flows out from the P-type pad electrode (31) in a bent manner, and the light extraction efficiency is improved.
The P-type pad electrode (31) is formed on the P-type semiconductor layer (25) or the transparent conductive layer (51). An N-type pad electrode (35) is formed on the N-type semiconductor layer (21) exposed from the active layer (23) and the P-type semiconductor layer (25).
The P-type finger electrode (33) is formed by extending the P-type pad electrode (31) toward the N-type pad electrode (35). The N-type finger electrode (37) is extended from the N-type pad electrode (31) and formed to surround the P-type finger electrode (33). The electrode layer (30) including the P-type pad electrode (31), the N-type pad electrode (35), the P-type finger electrode (33), and the N-type finger electrode (37) may have various forms in order to effectively diffuse the current.
The electrode layer (30) can be formed by a known deposition method such as electron beam evaporation, high-frequency induction evaporation, magnetron sputtering, or the like.
An upper reflective layer (40) is formed on the electrode layer (30). The upper reflective layer (40, 40a or 40b) may be aluminum (Al), silver (Ag) or dbr (distributed Bragg reflector). The upper reflective layer (40) prevents light totally reflected by the passivation layer (60) from being absorbed by the conductive metal layer, thereby improving light extraction efficiency.
When the upper reflective layer (40) is a DBR, the upper reflective layer (40) may have a structure in which insulating films having different refractive indices are alternately stacked. The low refractive index layer may be silicon oxide or aluminum oxide (Al)2O3) The film, high refractive index layer may be silicon nitride or titanium oxide (TiO)2) A film.
The upper reflection layer (40) etches away a part of the region on the P-type pad electrode (31) and the N-type pad electrode (35) to form an opening for wire bonding.
A passivation layer (60) is formed to cover the light-emitting layer (20) and the electrode layer (30). The passivation layer (60) is formed to prevent a decrease in light emitting efficiency due to physical, chemical, and electrical damage. The passivation layer (60) may contain a fluorescent substance for forming a white light emitting diode. The fluorescent substance may be a yellow fluorescent substance yag (yttrium aluminum garnet).
Light emitted from the light emitting structure may be reflected by the passivation layer (60). The reflected light can be reflected again by the upper reflection layer (40) and emitted out, thereby improving the external light extraction efficiency of the light emitting diode.
Fig. 4 is a cross-sectional view of an electrode layer of a light emitting diode according to an embodiment of the invention.
Referring to fig. 4, the electrode layer (30) may have a multi-layer structure including an ohmic contact layer (71) formed on the P-type semiconductor layer or the transparent electrode layer, a lower reflective layer (73) formed on the ohmic contact layer (71), a stress relaxation layer (75) formed on the lower reflective layer (73), and a conductive metal layer (77).
The ohmic contact layer (71) may include chromium (Cr), and is formed to realize ohmic contact between the P-type semiconductor layer or the transparent conductive layer and the electrode layer (30).
The lower reflection layer (73) contains Aluminum (AL) or silver (Ag), and reflects light emitted from the active region, thereby preventing the light from being absorbed by the conductive metal layer (77).
The stress relaxation layer (75) includes nickel (Ni), titanium (Ti), or chromium (Cr), so that ohmic contact between the lower reflection layer (73) and the conductive metal layer (77) can be achieved.
The conductive metal layer (77) may include platinum (Pt) or gold (Au).
The upper reflective layer (40) is formed on the conductive metal layer (77). The upper reflection layer (40) can reflect the light totally reflected by the passivation layer (60) again, thereby improving the external light extraction efficiency.
The above are preferred embodiments of the present invention, and all changes made according to the technical scheme of the present invention that produce functional effects do not exceed the scope of the technical scheme of the present invention belong to the protection scope of the present invention.
Claims (10)
1. A light-emitting diode is characterized by comprising a substrate, an N-type semiconductor layer, an active layer and a P-type semiconductor layer which are sequentially arranged from bottom to top, wherein the areas of the active layer and the P-type semiconductor layer are smaller than that of the N-type semiconductor layer so as to expose part of the N-type semiconductor layer; the N-type pad electrode, the P-type pad electrode and the finger electrode respectively comprise an ohmic contact layer, a lower reflecting layer, a stress relieving layer, a conductive metal layer and an upper reflecting layer which are sequentially arranged from bottom to top.
2. The led of claim 1, wherein the ohmic contact layer is formed of chromium, the lower reflective layer is formed of aluminum or silver, the stress relaxation layer is formed of nickel, titanium, or chromium, and the conductive metal layer is formed of platinum or gold.
3. The led of claim 1, wherein said upper reflective layer is formed of aluminum, silver or DBR.
4. The light-emitting diode of claim 1, wherein a transparent electrode layer is further disposed between the P-type semiconductor layer and the P-type pad electrode.
5. The light-emitting diode according to claim 4, wherein a current blocking layer is further disposed in a partial region between the P-type semiconductor layer and the transparent electrode layer, and the current blocking layer is located right below the P-type pad electrode.
6. A method for manufacturing a light emitting diode according to any one of claims 1 to 5, wherein first, an ohmic contact layer is formed on the P-type semiconductor layer; then, forming a lower reflection layer on the ohmic contact layer; then, forming a stress relaxation layer on the lower reflection layer; then, forming a conductive metal layer on the stress relaxation layer, and finally forming an upper reflection layer on the conductive metal layer; in the step of forming the upper reflective layer, the upper reflective layer is formed on a partial region of the conductive metal layer of the N-type pad electrode and the P-type pad electrode and on the entire conductive metal layer of the finger electrode.
7. The manufacturing method according to claim 6, characterized in that: the ohmic contact layer is formed of chromium, the lower reflection layer is formed of aluminum or silver, the stress relaxation layer is formed of nickel, titanium or chromium, and the conductive metal layer is formed of platinum or gold.
8. The manufacturing method according to claim 6, characterized in that: and in the process of forming the upper reflecting layer, the upper reflecting layer is formed on the conductive metal layers of the N-type pad electrode, the P-type pad electrode and the finger electrode, and the upper reflecting layer on partial areas of the N-type pad electrode and the P-type pad electrode is removed.
9. The manufacturing method according to claim 6, characterized in that: the upper reflective layer is formed of aluminum, silver, or DBR.
10. The manufacturing method according to claim 6, characterized in that: further comprising a process of forming a current blocking layer on a partial region of the P-type semiconductor layer, and a process of forming a transparent conductive layer on the current blocking layer and the P-type semiconductor layer, and forming a P-type pad electrode directly above the region where the current blocking layer is formed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810987785.4A CN109148663B (en) | 2018-08-28 | 2018-08-28 | Light emitting diode and method for manufacturing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810987785.4A CN109148663B (en) | 2018-08-28 | 2018-08-28 | Light emitting diode and method for manufacturing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109148663A CN109148663A (en) | 2019-01-04 |
| CN109148663B true CN109148663B (en) | 2020-05-12 |
Family
ID=64828649
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810987785.4A Active CN109148663B (en) | 2018-08-28 | 2018-08-28 | Light emitting diode and method for manufacturing the same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109148663B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110034219B (en) * | 2019-04-28 | 2024-05-17 | 福建兆元光电有限公司 | Light emitting diode and method of manufacturing the same |
| CN115863514B (en) * | 2023-03-03 | 2023-05-12 | 江西兆驰半导体有限公司 | Vertical LED chip and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101645482A (en) * | 2008-08-05 | 2010-02-10 | 夏普株式会社 | Nitride semiconductor light emitting device and method of manufacturing the same |
| CN102169942A (en) * | 2010-02-26 | 2011-08-31 | 丰田合成株式会社 | Semiconductor light-emitting element |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101763072B1 (en) * | 2016-06-09 | 2017-08-04 | 고려대학교 산학협력단 | LED Device For Enhancing Light Extraction Efficiency And Current Injection Efficiency |
-
2018
- 2018-08-28 CN CN201810987785.4A patent/CN109148663B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101645482A (en) * | 2008-08-05 | 2010-02-10 | 夏普株式会社 | Nitride semiconductor light emitting device and method of manufacturing the same |
| CN102169942A (en) * | 2010-02-26 | 2011-08-31 | 丰田合成株式会社 | Semiconductor light-emitting element |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109148663A (en) | 2019-01-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10749075B2 (en) | Semiconductor light-emitting device | |
| KR100631840B1 (en) | Nitride semiconductor light emitting device for flip chip | |
| TWI472062B (en) | Semiconductor light emitting device and manufacturing method thereof | |
| KR101007139B1 (en) | Light emitting device and method for fabricating the same | |
| EP3404726B1 (en) | Ultraviolet light-emitting device | |
| US11430934B2 (en) | Light-emitting diode device | |
| CN102386295A (en) | Light-emitting element | |
| KR20140066481A (en) | Light emitting diode with excellent current spreading effect and method of manufacturing the same | |
| KR20080049724A (en) | Semiconductor light-emitting device and method for making same | |
| US8710486B2 (en) | Optoelectronic semiconductor chip and method for manufacturing a contact structure for such a chip | |
| JP2019207925A (en) | Semiconductor light-emitting element and method for manufacturing semiconductor light-emitting element | |
| CN113707782B (en) | Flip-chip light emitting diode and preparation method thereof | |
| US11329195B2 (en) | Semiconductor light-emitting device | |
| KR100856251B1 (en) | Manufacturing method of vertical nitride semiconductor light emitting device | |
| KR101154750B1 (en) | Light emitting device and method for fabricating the same | |
| CN109148663B (en) | Light emitting diode and method for manufacturing the same | |
| KR100682878B1 (en) | Flip-chip light emitting device | |
| CN112635632B (en) | Light emitting diode and method for manufacturing the same | |
| CN110034219B (en) | Light emitting diode and method of manufacturing the same | |
| CN210040240U (en) | Light emitting diode | |
| CN210040239U (en) | Light emitting diode | |
| US10910538B2 (en) | Optoelectronic semiconductor component and method for producing an optoelectronic semiconductor component | |
| KR20130113267A (en) | Light emitting diode array with excellent light emtting efficiency | |
| KR101960611B1 (en) | The Light Emitting Diode Flip-Chip | |
| KR100635159B1 (en) | Nitride semiconductor light emitting device and method of manufacturing the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |