CN110047982B - Light emitting diode, epitaxial wafer and preparation method thereof - Google Patents

Light emitting diode, epitaxial wafer and preparation method thereof Download PDF

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CN110047982B
CN110047982B CN201910145355.2A CN201910145355A CN110047982B CN 110047982 B CN110047982 B CN 110047982B CN 201910145355 A CN201910145355 A CN 201910145355A CN 110047982 B CN110047982 B CN 110047982B
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gallium nitride
thin film
nitride layer
gan
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CN110047982A (en
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曹阳
乔楠
郭炳磊
吕蒙普
胡加辉
李鹏
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Boe Huacan Optoelectronics Suzhou Co ltd
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HC Semitek Suzhou Co Ltd
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    • 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
    • H01L33/005—Processes
    • H01L33/0062—Processes for devices with an active region comprising only III-V compounds
    • H01L33/0075—Processes for devices with an active region comprising only III-V compounds comprising nitride compounds
    • 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
    • H01L33/02—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 semiconductor bodies
    • H01L33/04—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 semiconductor bodies with a quantum effect structure or superlattice, e.g. tunnel junction
    • H01L33/06—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 semiconductor bodies with a quantum effect structure or superlattice, e.g. tunnel junction within the light emitting region, e.g. quantum confinement structure or tunnel barrier
    • 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
    • H01L33/02—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 semiconductor bodies
    • H01L33/12—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 semiconductor bodies with a stress relaxation structure, e.g. buffer layer
    • 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
    • H01L33/02—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 semiconductor bodies
    • H01L33/14—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 semiconductor bodies with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
    • H01L33/145—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 semiconductor bodies with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure with a current-blocking structure
    • 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
    • H01L33/02—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 semiconductor bodies
    • H01L33/26—Materials of the light emitting region
    • H01L33/30—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table
    • H01L33/32—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table containing nitrogen

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Abstract

The invention discloses a light emitting diode, an epitaxial wafer and a preparation method thereof, and belongs to the technical field of epitaxy. This emitting diode epitaxial wafer includes: the GaN-based LED chip comprises a substrate, and a GaN buffer layer, an undoped GaN layer, an N-type doped GaN layer, an N-type AlGaN layer, a multi-quantum well layer, an electronic barrier layer, a P-type doped GaN layer and a P-type contact layer which are sequentially stacked on the substrate; the electronic barrier layer comprises a gallium nitride layer and a silver thin film layer, the silver thin film layer is positioned on the surface of the gallium nitride layer, which is in contact with the P-type doped gallium nitride layer, and a silver-gallium metal compound is distributed on one surface of the gallium nitride layer, which is in contact with the silver thin film layer. Through the electron barrier layer that contains gallium nitride layer and silver thin film layer, promoted the effect that the electron blocked on the one hand, on the other hand has guaranteed the smooth passing through of hole.

Description

Light emitting diode, epitaxial wafer and preparation method thereof
Technical Field
The invention relates to the technical field of epitaxy, in particular to a light-emitting diode, an epitaxial wafer and a preparation method thereof.
Background
Currently, gallium nitride (GaN) -based Light Emitting Diodes (LEDs) are receiving more and more attention and research. The epitaxial wafer is a core part of the GaN-based LED, and the structure of the epitaxial wafer comprises: the GaN-based light-emitting diode comprises a substrate, a GaN buffer layer, an undoped GaN layer, an N-type doped GaN layer, an N-type AlGaN layer, a multi-Quantum Well (MQW) layer, a P-type AlGaN layer, a P-type doped GaN layer and a P-type contact layer.
When current flows, electrons in the N-type doped GaN layer and holes in the P-type doped GaN layer enter the MQW layer, and light is recombined in the MQW layer. Electrons and holes recombine in other layers outside the MQW layer and do not emit light, which is referred to as non-radiative recombination. In order to reduce the occurrence of non-radiative recombination, a P-type AlGaN layer is arranged in the epitaxial wafer structure, and the P-type AlGaN layer has the function of blocking electrons in the N-type doped GaN layer from overflowing from the MQW layer so as to increase the luminescence recombination in the MQW layer.
However, the P-type AlGaN layer in the current epitaxial wafer structure generally has poor crystal quality, which is not favorable for blocking electrons on one hand, and is also unfavorable for holes to enter the MQW layer through the P-type AlGaN layer on the other hand.
Disclosure of Invention
The embodiment of the invention provides a light-emitting diode, an epitaxial wafer and a preparation method thereof, aiming at improving the electron blocking effect of a P-type AlGaN layer and ensuring the smooth passing of holes. The technical scheme is as follows:
in one aspect, an embodiment of the present invention provides an led epitaxial wafer, where the led epitaxial wafer includes: the GaN-based LED chip comprises a substrate, and a GaN buffer layer, an undoped GaN layer, an N-type doped GaN layer, an N-type AlGaN layer, a multi-quantum well layer, an electronic barrier layer, a P-type doped GaN layer and a P-type contact layer which are sequentially stacked on the substrate; the electronic barrier layer comprises a gallium nitride layer and a silver thin film layer, the silver thin film layer is positioned on the surface of the gallium nitride layer, which is in contact with the P-type doped gallium nitride layer, and a silver-gallium metal compound is distributed on one surface of the gallium nitride layer, which is in contact with the silver thin film layer.
In an implementation manner of the embodiment of the present invention, the thickness range of the gallium nitride layer is 50nm to 150nm, and the thickness range of the silver thin film layer is 5nm to 8 nm.
In one implementation manner of the embodiment of the invention, the molar doping amount of the silver in the gallium nitride layer is between 0.1 and 0.3.
In an implementation manner of the embodiment of the present invention, the electron blocking layer further includes an aluminum gallium nitride layer, and the aluminum gallium nitride layer is located between the gallium nitride layer and the multiple quantum well layer.
In an implementation manner of the embodiment of the present invention, the thicknesses of the high-temperature aluminum nitride sublayer and the aluminum gallium nitride layer range from 50nm to 150 nm.
In another aspect, an embodiment of the present invention further provides a light emitting diode, where the light emitting diode includes the light emitting diode epitaxial wafer according to any one of the foregoing embodiments.
On the other hand, the embodiment of the invention also provides a preparation method of the light emitting diode epitaxial wafer, which comprises the following steps:
growing a gallium nitride buffer layer, an undoped gallium nitride layer, an N-type doped gallium nitride layer, an N-type aluminum gallium nitride layer and a multi-quantum well layer on a substrate in sequence;
growing an electronic barrier layer on the multi-quantum well layer, wherein the electronic barrier layer comprises a gallium nitride layer and a silver thin film layer, the silver thin film layer is positioned on the surface of the gallium nitride layer, and a silver-gallium metal compound is distributed on one surface of the gallium nitride layer, which is in contact with the silver thin film layer;
and sequentially growing a P-type doped gallium nitride layer and a P-type contact layer on the silver thin film layer of the electron blocking layer.
In an implementation manner of the embodiment of the present invention, the thickness range of the gallium nitride layer is 50nm to 150nm, and the thickness range of the silver thin film layer is 5nm to 8 nm.
In one implementation manner of the embodiment of the present invention, the growing an electron blocking layer on the multiple quantum well layer includes:
growing the gallium nitride layer on the multi-quantum well layer under the conditions that the growth temperature range is 850-1080 ℃ and the growth pressure range is 200-500 Torr in a metal organic compound chemical vapor deposition device;
and sputtering a layer of silver on the gallium nitride layer by adopting a sputtering process under the conditions that the working temperature range is 100-300 ℃, the working pressure range is 1-5Pa and the sputtering power range is 10-50W in physical vapor deposition equipment to obtain the silver thin film layer.
In one implementation manner of the embodiment of the present invention, the growing an electron blocking layer on the multiple quantum well layer further includes:
before growing the gallium nitride layer, growing the aluminum gallium nitride layer on the multi-quantum well layer under the conditions that the growth temperature range is 850-1080 ℃ and the growth pressure range is 200-500 Torr in the metal organic compound chemical vapor deposition equipment.
The technical scheme provided by the embodiment of the invention has the following beneficial effects:
in the embodiment of the invention, an electronic barrier layer is arranged between the multi-quantum well layer and the P-type doped gallium nitride layer, the electronic barrier layer comprises a gallium nitride layer and a silver thin film layer, the silver thin film layer is positioned on the surface of the gallium nitride layer, which is in contact with the P-type doped gallium nitride layer, and a silver-gallium metal compound is distributed on the surface of the gallium nitride layer, which is in contact with the silver thin film layer. The silver thin film layer is formed on at least one surface of the gallium nitride layer, the surfaces of the silver thin film layer, which are in contact with the gallium nitride layer, interact to form a silver-gallium metal compound, electrons overflowing from the multi-quantum well layer are blocked by the silver-gallium metal compound, the electrons are prevented from being compounded with holes by the P-type doped gallium nitride layer, and the concentration of the holes entering the multi-quantum well layer is increased; in addition, due to the influence of the local state density, the silver-gallium metal compound is beneficial to improving the hole concentration of a combined film layer growing on the electron blocking layer and the P-type doped gallium nitride layer and improving the effective injection of the hole of the P-type doped gallium nitride layer, so that the quantum well region carrier recombination efficiency is improved, and the luminous efficiency of the light-emitting diode with the epitaxial wafer is improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an led epitaxial wafer according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of another light emitting diode epitaxial wafer according to an embodiment of the present invention;
fig. 3 is a method for manufacturing an epitaxial wafer of a light emitting diode according to an embodiment of the present invention;
fig. 4 is another method for manufacturing an epitaxial wafer of a light emitting diode according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
Fig. 1 is a schematic structural diagram of an led epitaxial wafer according to an embodiment of the present invention. Referring to fig. 1, the light emitting diode epitaxial wafer may include: the GaN-based light-emitting diode comprises a substrate 100, and a GaN buffer layer 101, an undoped GaN layer 102, an N-type doped GaN layer 103, an N-type AlGaN layer 104, a multi-quantum well layer 105, an electron blocking layer 106, a P-type doped GaN layer 107 and a P-type contact layer 108 which are sequentially stacked on the substrate 100.
The electron blocking layer 106 may include a GaN layer 161 and an Ag thin film layer 162, the Ag thin film layer 162 is located on a surface of the GaN layer 161 contacting the P-type doped GaN layer 107, and AgGa metal compounds are distributed on a surface of the GaN layer 161 contacting the Ag thin film layer 162.
In the embodiment of the present invention, the Ag thin film layer 162 is formed on the GaN layer 161 by a sputtering process, and since the temperature of Ag sputtered on the surface of the GaN layer 161 is high during sputtering, Ag reacts with GaN on the surface of the GaN layer 161 to form the aforementioned AgGa metal compound. The AgGa metal compound includes a compound in a metal alloy state, and an AgGaN compound.
In the embodiment of the invention, an electronic barrier layer is arranged between the multi-quantum well layer and the P-type doped GaN layer, the electronic barrier layer comprises a GaN layer and an Ag thin film layer, the Ag thin film layer is positioned on the surface of the GaN layer, which is in contact with the P-type doped GaN layer, and AgGa metal compounds are distributed on the surface of the GaN layer, which is in contact with the Ag thin film layer. The Ag thin film layer is formed on at least one surface of the GaN layer, the surfaces of the Ag thin film layer and the GaN layer which are in contact interact to form an AgGa metal compound, electrons overflowing from the multi-quantum well layer are blocked by the AgGa-doped metal compound, the electrons are prevented from being compounded with holes through the P-type doped GaN layer, and the concentration of the holes entering the multi-quantum well layer is increased; in addition, due to the influence of the local state density, the AgGa metal compound is beneficial to improving the hole concentration of a combined film layer growing on the electron blocking layer and the P-type doped GaN layer and improving the effective injection of the hole of the P-type doped GaN layer, so that the carrier recombination efficiency of a quantum well region is improved, and the luminous efficiency of the light-emitting diode with the epitaxial wafer is improved.
The local density of states refers to the distribution of electron wave functions at specific positions, and affects the electron distribution outside the atomic nucleus, and further affects the charge distribution of the compound. The AgGa metal compound has a low electronic potential, so that electrons are trapped and holes are left to serve as positive charge centers, and the concentration of the holes entering the electron blocking layer and the combined film layer of the P-type doped GaN layer is high.
In the embodiment of the invention, the thickness of the GaN layer 161 may range from 50nm to 150nm, and the thickness of the Ag thin film layer 162 may range from 5nm to 8 nm.
In this implementation, the GaN layer 161 with a certain thickness is provided to ensure that Ag does not damage the multiple quantum well layer during sputtering, but the thickness of the GaN layer 161 cannot be too thick, which results in too large thickness of the whole epitaxial wafer and affects the thinning of the device. In addition, the blocking of electrons is realized by sputtering an Ag film with a certain thickness, and meanwhile, the Ag film is small in thickness and in a transparent state, so that the light emitting of the whole device is not influenced.
Illustratively, the thickness of the GaN layer 161 may be 100nm, and the thickness of the Ag thin film layer 162 may be 5 nm.
In the embodiment of the present invention, the molar doping amount of Ag in the GaN layer 161 is between 0.1 and 0.3.
Here, the molar doping amount of Ag means a ratio of the molar amount (moles) of Ag to the volume (liters) of the GaN layer 161 in the entire GaN layer 161. The molar doping amount of Ag is related to the sputtering process, and if the sputtering temperature is too low, the molar doping amount of Ag is low, and the AgGa metal compound is less, so that the effect of the electron blocking layer is not good. However, in order to increase the molar incorporation amount of Ag, parameters such as a sputtering temperature need to be increased, and on the other hand, the requirement for a sputtering apparatus is high, and on the other hand, the grown film layer is easily damaged.
Fig. 2 is a schematic structural diagram of another light emitting diode epitaxial wafer according to an embodiment of the present invention. Referring to fig. 2, the structure of the light emitting diode epitaxial wafer shown in fig. 2 is different from that of the light emitting diode epitaxial wafer shown in fig. 1 in that the electron blocking layer 106 further includes an AlGaN layer 163, and the AlGaN layer 163 is located between the GaN layer 161 and the multiple quantum well layer 105.
In this embodiment, an AlGaN layer 163 is provided between the GaN layer 161 and the multiple quantum well layer 105, and the AlGaN layer 163 can further block electron overflow.
In embodiments of the present invention, the thickness of AlGaN layer 163 may range from 50nm to 150 nm.
In this implementation, the blocking effect on electrons is ensured by providing the AlGaN layer 163 with a certain thickness, but the thickness of the AlGaN layer 163 cannot be too thick, which results in too large thickness of the entire epitaxial wafer, and thus the device is reduced in thickness.
Illustratively, the AlGaN layer 163 may have a thickness of 50 nm.
In the embodiment of the present invention, AlGaN layer 163 is a P-type doped AlGaN layer with a doping concentration of 2 × 1017～2×1018cm-3In the meantime.
In this embodiment, although the AlGaN layer 163 having a constant doping concentration ensures an electron blocking effect, the doping concentration of the AlGaN layer 163 cannot be excessively large to affect hole injection into the multiple quantum well layer.
In this implementation, the P-type doped AlGaN layer is formed by doping a trivalent element (e.g., boron) into AlGaN layer 163, and the P-type doping concentration in AlGaN layer 163 is constant along the growth direction of AlGaN layer 163.
In the embodiment of the present invention, the Substrate may be a silicon dioxide Patterned Sapphire Substrate (PSS).
Fig. 3 is a flowchart of a method for manufacturing an epitaxial wafer of a light emitting diode according to an embodiment of the invention. The method is used for preparing an epitaxial wafer shown in fig. 1, and referring to fig. 3, the method comprises the following steps:
step 201: and a GaN buffer layer, an undoped GaN layer, an N-type doped GaN layer, an N-type AlGaN layer and a multi-quantum well layer are sequentially grown on the substrate.
In the embodiment of the present invention, the substrate may employ silicon dioxide PSS.
Step 202: and growing an electron barrier layer on the multi-quantum well layer.
The electronic barrier layer can comprise a GaN layer and an Ag thin film layer, the Ag thin film layer is located on the surface, contacting the GaN layer and the P-type doped GaN layer, of the GaN layer, and AgGa metal compounds are distributed on the surface, contacting the GaN layer and the Ag thin film layer, of the GaN layer.
In the embodiment of the invention, the Ag thin film layer is made on the GaN layer through a sputtering process, and the Ag reacts with the GaN on the surface of the GaN layer due to the high temperature of the Ag sputtered on the surface of the GaN layer during sputtering to form the AgGa metal compound. The AgGa metal compound includes a compound in a metal alloy state, and an AgGaN compound.
In the embodiment of the invention, the thickness range of the GaN layer can be 50nm-150nm, and the thickness range of the Ag thin film layer can be 5-8 nm.
In the implementation mode, the GaN layer with a certain thickness is arranged to ensure that Ag does not damage the multi-quantum well layer in the sputtering process, but the thickness of the GaN layer cannot be too thick to cause the thickness of the whole epitaxial wafer to be too large, so that the lightening and thinning of a device are influenced. In addition, the blocking of electrons is realized by sputtering an Ag film with a certain thickness, and meanwhile, the Ag film is small in thickness and in a transparent state, so that the light emitting of the whole device is not influenced.
Illustratively, the thickness of the GaN layer may be 100nm, and the thickness of the Ag thin film layer may be 5 nm.
In the embodiment of the invention, the molar doping amount of Ag in the GaN layer is between 0.1 and 0.3.
Here, the molar doping amount of Ag means a ratio of the molar amount (moles) of Ag to the volume (liter) of the GaN layer in the entire GaN layer. The molar doping amount of Ag is related to the sputtering process, and if the sputtering temperature is too low, the molar doping amount of Ag is low, and the AgGa metal compound is less, so that the effect of the electron blocking layer is not good. However, in order to increase the molar incorporation amount of Ag, parameters such as a sputtering temperature need to be increased, and on the other hand, the requirement for a sputtering apparatus is high, and on the other hand, the grown film layer is easily damaged.
Optionally, the electron blocking layer may further include an AlGaN layer, and the AlGaN layer is located between the GaN layer and the multiple quantum well layer.
In this embodiment mode, an AlGaN layer is provided between the GaN layer and the multiple quantum well layer, and the AlGaN layer can further block electron overflow.
In embodiments of the present invention, the AlGaN layer may have a thickness ranging from 50nm to 150 nm.
In this implementation, the effect of blocking electrons is guaranteed by setting an AlGaN layer with a certain thickness, but the thickness of the AlGaN layer cannot be too thick, so that the thickness of the whole epitaxial wafer is too large, which affects the lightness and thinness of the device.
Illustratively, the AlGaN layer may have a thickness of 50 nm.
In the embodiment of the invention, the AlGaN layer is a P-type doped ALGAN layer, and the doping concentration is 2 × 1017～2×1018cm-3In the meantime.
In this embodiment, the electron blocking effect is ensured by providing the AlGaN layer having a certain doping concentration, but the doping concentration of the AlGaN layer cannot be excessively large to affect the hole injection into the multiple quantum well layer.
In this implementation, the P-type doped AlGaN layer is formed by doping a trivalent element (e.g., boron) into the AlGaN layer, and the P-type doping concentration in the AlGaN layer is constant along the growth direction of the AlGaN layer.
Step 203: and sequentially growing a P-type doped GaN layer and a P-type contact layer on the electron blocking layer.
In the embodiment of the invention, an electronic barrier layer is arranged between the multi-quantum well layer and the P-type doped GaN layer, the electronic barrier layer comprises a GaN layer and an Ag thin film layer, the Ag thin film layer is positioned on the surface of the GaN layer, which is in contact with the P-type doped GaN layer, and AgGa metal compounds are distributed on the surface of the GaN layer, which is in contact with the Ag thin film layer. The Ag thin film layer is formed on at least one surface of the GaN layer, the surfaces of the Ag thin film layer and the GaN layer which are in contact interact to form an AgGa metal compound, electrons overflowing from the multi-quantum well layer are blocked by the AgGa-doped metal compound, the electrons are prevented from being compounded with holes through the P-type doped GaN layer, and the concentration of the holes entering the multi-quantum well layer is increased; in addition, due to the influence of the local state density, the AgGa metal compound is beneficial to improving the hole concentration of a combined film layer growing on the electron blocking layer and the P-type doped GaN layer and improving the effective injection of the hole of the P-type doped GaN layer, so that the carrier recombination efficiency of a quantum well region is improved, and the luminous efficiency of the light-emitting diode with the epitaxial wafer is improved.
FIG. 4 is a flow chart of another GaN-based light emitting diode epitaxial wafer manufacturing method according to an embodiment of the invention. The method is used for preparing the epitaxial wafer shown in fig. 1 or fig. 2, and referring to fig. 4, the method comprises the following steps:
step 301: a GaN buffer layer is grown on the substrate.
In the embodiment of the present invention, the substrate may employ silicon dioxide PSS. Prior to growing the buffer layer, the method may further comprise: putting the substrate in a hydrogen atmosphere for annealing treatment for 8 minutes, and cleaning the surface of the substrate, wherein the temperature can be between 1000 ℃ and 1200 ℃; the substrate is then subjected to a nitridation process.
In an embodiment of the present invention, the step may include: the temperature is adjusted to 400-600 ℃, a GaN buffer layer with the thickness of 15-35 nm is grown, and the growth pressure interval can be 400-600 Torr.
After the buffer layer growth is completed, the method may further include: the buffer layer is annealed at a temperature of between 1000 deg.C and 1200 deg.C for a time of between 5 minutes and 10 minutes at a pressure of between 400Torr and 600 Torr.
Step 302: and growing an undoped GaN layer on the GaN buffer layer.
In an embodiment of the present invention, the step may include: the temperature is adjusted to 1000-1100 deg.C, and an undoped GaN layer with a thickness of 1-5.0 μm is grown under a pressure of 100-500 Torr.
Step 303: and growing an N-type doped GaN layer on the undoped GaN layer.
After the growth of the undoped GaN layer is finished, a Si-doped N-type doped GaN layer is grown, the thickness can be 1.0-5.0 microns, the growth temperature can be 1000-1200 ℃, the pressure can be 100-500 Torr, and the Si doping concentration can be 1018cm-3～1019cm-3In the meantime.
Step 304: and growing an N-type AlGaN layer on the N-type doped GaN layer.
After the growth of the N-type doped GaN layer is finished, an N-type AlGaN layer is grown, the thickness of the N-type AlGaN layer can be between 50nm and 180nm, the growth temperature can be between 800 ℃ and 1100 ℃, the growth pressure can be between 300Torr and 500Torr, and the molar doping amount of Al can be between 0 and 0.3.
Step 305: and growing a multi-quantum well layer on the N-type AlGaN layer.
After the growth of the N-type AlGaN layer is finished, growing a multi-quantum well layer, wherein the period of the multi-quantum well layer is 3-15 periods of InxGa1-xN(0<x<1) The well thickness can be about 3nm, the growth temperature can be in the range of 720-829 ℃, and the pressure can be in the range of 100Torr and 500 Torr; the barrier thickness is between 9nm and 20nm, the growth temperature is between 850 ℃ and 959 ℃, and the growth pressure is between 100Torr and 500 Torr.
Step 306: and growing an electron barrier layer on the multi-quantum well layer.
In an embodiment of the present invention, growing an electron blocking layer on the multiple quantum well layer may include:
growing a GaN layer on the multi-quantum well layer under the conditions that the growth temperature range is 850-1080 ℃ and the growth pressure range is 200-500 Torr in a metal organic compound chemical vapor deposition device;
sputtering a layer of Ag on the GaN layer by a sputtering process under the conditions that the working temperature range is 100-300 ℃, the working pressure range is 1-5Pa and the sputtering power range is 10-50W in physical vapor deposition equipment to obtain an Ag thin film layer.
The electronic barrier layer grown by the steps comprises a GaN layer and an Ag thin film layer, wherein the Ag thin film layer is positioned on the surface of the GaN layer, which is in contact with the P-type doped GaN layer, and AgGa metal compounds are distributed on the surface of the GaN layer, which is in contact with the Ag thin film layer.
In the embodiment of the invention, the Ag thin film layer is made on the GaN layer through a sputtering process, and the Ag reacts with the GaN on the surface of the GaN layer due to the high temperature of the Ag sputtered on the surface of the GaN layer during sputtering to form the AgGa metal compound. The AgGa metal compound includes a compound in a metal alloy state, and an AgGaN compound.
In the embodiment of the invention, the thickness range of the GaN layer can be 50nm-150nm, and the thickness range of the Ag thin film layer can be 5-8 nm.
In the implementation mode, the GaN layer with a certain thickness is arranged to ensure that Ag does not damage the multi-quantum well layer in the sputtering process, but the thickness of the GaN layer cannot be too thick to cause the thickness of the whole epitaxial wafer to be too large, so that the lightening and thinning of a device are influenced. In addition, the blocking of electrons is realized by sputtering an Ag film with a certain thickness, and meanwhile, the Ag film is small in thickness and in a transparent state, so that the light emitting of the whole device is not influenced.
Illustratively, the thickness of the GaN layer may be 100nm, and the thickness of the Ag thin film layer may be 5 nm.
In the embodiment of the invention, the molar doping amount of Ag in the GaN layer is between 0.1 and 0.3.
Here, the molar doping amount of Ag means a ratio of the molar amount (moles) of Ag to the volume (liter) of the GaN layer in the entire GaN layer. The molar doping amount of Ag is related to the sputtering process, and if the sputtering temperature is too low, the molar doping amount of Ag is low, and the AgGa metal compound is less, so that the effect of the electron blocking layer is not good. However, in order to increase the molar incorporation amount of Ag, parameters such as a sputtering temperature need to be increased, and on the other hand, the requirement for a sputtering apparatus is high, and on the other hand, the grown film layer is easily damaged.
Optionally, growing an electron blocking layer on the multiple quantum well layer, and may further include:
before growing the GaN layer, growing the AlGaN layer on the multi-quantum well layer under the conditions that the growth temperature ranges from 850 ℃ to 1080 ℃ and the growth pressure ranges from 200Torr to 500Torr in a metal organic compound chemical vapor deposition device.
The electron barrier layer obtained through the growth in the steps further comprises an AlGaN layer, and the AlGaN layer is located between the GaN layer and the multi-quantum well layer.
In this embodiment mode, an AlGaN layer is provided between the GaN layer and the multiple quantum well layer, and the AlGaN layer can further block electron overflow.
In embodiments of the present invention, the AlGaN layer may have a thickness ranging from 50nm to 150 nm.
In this implementation, the effect of blocking electrons is guaranteed by setting an AlGaN layer with a certain thickness, but the thickness of the AlGaN layer cannot be too thick, so that the thickness of the whole epitaxial wafer is too large, which affects the lightness and thinness of the device.
Illustratively, the AlGaN layer may have a thickness of 50 nm.
In the embodiment of the invention, the AlGaN layer is a P-type doped ALGAN layer, and the doping concentration is 2 × 1017～2×1018cm-3In the meantime.
In this embodiment, the electron blocking effect is ensured by providing the AlGaN layer having a certain doping concentration, but the doping concentration of the AlGaN layer cannot be excessively large to affect the hole injection into the multiple quantum well layer.
In this implementation, the P-type doped AlGaN layer is formed by doping a trivalent element (e.g., boron) into the AlGaN layer, and the P-type doping concentration in the AlGaN layer is constant along the growth direction of the AlGaN layer.
Step 307: and growing a P-type doped GaN layer on the electron blocking layer.
After the growth of the electron blocking layer is finished, a P-type doped GaN layer grows on the electron blocking layer, the thickness can be between 100nm and 800nm, the growth temperature can be between 800 ℃ and 950 ℃, and the growth pressure interval can be between 200Torr and 300 Torr.
Step 308: and growing a P-type contact layer on the P-type doped GaN layer.
After the P-type doped GaN layer is finished, a P-type contact layer grows on the P-type doped GaN layer, the thickness can be 5nm to 300nm, the growth temperature range can be 800 ℃ to 950 ℃, and the growth pressure range can be 100Torr to 300 Torr.
After the growth is finished, the temperature of the reaction cavity is reduced, annealing treatment is carried out in the nitrogen atmosphere, the annealing temperature range can be 650-850 ℃, the annealing treatment is carried out for 5-15 minutes, and the temperature is reduced to room temperature, and the epitaxial growth is finished.
The embodiment of the invention also provides the light-emitting diode which comprises the light-emitting diode epitaxial wafer.
In the embodiment of the invention, an electronic barrier layer is arranged between the multi-quantum well layer and the P-type doped GaN layer, the electronic barrier layer comprises a GaN layer and an Ag thin film layer, the Ag thin film layer is positioned on the surface of the GaN layer, which is in contact with the P-type doped GaN layer, and AgGa metal compounds are distributed on the surface of the GaN layer, which is in contact with the Ag thin film layer. The Ag thin film layer is formed on at least one surface of the GaN layer, the surfaces of the Ag thin film layer and the GaN layer which are in contact interact to form an AgGa metal compound, electrons overflowing from the multi-quantum well layer are blocked by the AgGa-doped metal compound, the electrons are prevented from being compounded with holes through the P-type doped GaN layer, and the concentration of the holes entering the multi-quantum well layer is increased; in addition, due to the influence of the local state density, the AgGa metal compound is beneficial to improving the hole concentration of a combined film layer growing on the electron blocking layer and the P-type doped GaN layer and improving the effective injection of the hole of the P-type doped GaN layer, so that the carrier recombination efficiency of a quantum well region is improved, and the luminous efficiency of the light-emitting diode with the epitaxial wafer is improved.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (10)

1. A light emitting diode epitaxial wafer, comprising: the GaN-based LED chip comprises a substrate, and a GaN buffer layer, an undoped GaN layer, an N-type doped GaN layer, an N-type AlGaN layer, a multi-quantum well layer, an electronic barrier layer, a P-type doped GaN layer and a P-type contact layer which are sequentially stacked on the substrate; the electronic barrier layer is characterized by comprising a gallium nitride layer and a silver thin film layer, wherein the silver thin film layer is positioned on the surface of the gallium nitride layer in contact with the P-type doped gallium nitride layer, and a silver-gallium metal compound is distributed on one surface of the gallium nitride layer in contact with the silver thin film layer.
2. The light-emitting diode epitaxial wafer according to claim 1, wherein the thickness of the gallium nitride layer is in a range of 50nm to 150nm, and the thickness of the silver thin film layer is in a range of 5nm to 8 nm.
3. The light-emitting diode epitaxial wafer according to claim 1, wherein the molar doping amount of silver in the gallium nitride layer is between 0.1 and 0.3.
4. The light emitting diode epitaxial wafer of any of claims 1 to 3, wherein the electron blocking layer further comprises an aluminum gallium nitride layer, the aluminum gallium nitride layer being located between the gallium nitride layer and the MQW layer.
5. The light-emitting diode epitaxial wafer according to claim 4, wherein the thickness of the aluminum gallium nitride layer is in a range of 50nm to 150 nm.
6. A light emitting diode comprising the light emitting diode epitaxial wafer as claimed in any one of claims 1 to 5.
7. A preparation method of a light emitting diode epitaxial wafer is characterized by comprising the following steps:
growing a gallium nitride buffer layer, an undoped gallium nitride layer, an N-type doped gallium nitride layer, an N-type aluminum gallium nitride layer and a multi-quantum well layer on a substrate in sequence;
growing an electronic barrier layer on the multi-quantum well layer, wherein the electronic barrier layer comprises a gallium nitride layer and a silver thin film layer, the silver thin film layer is positioned on the surface of the gallium nitride layer, and a silver-gallium metal compound is distributed on one surface of the gallium nitride layer, which is in contact with the silver thin film layer;
and sequentially growing a P-type doped gallium nitride layer and a P-type contact layer on the silver thin film layer of the electron blocking layer.
8. The method of claim 7, wherein the gallium nitride layer has a thickness in the range of 50nm to 150nm and the silver thin film layer has a thickness in the range of 5nm to 8 nm.
9. The method of claim 7 or 8, wherein growing an electron blocking layer on the MQW layer comprises:
growing the gallium nitride layer on the multi-quantum well layer under the conditions that the growth temperature range is 850-1080 ℃ and the growth pressure range is 200-500 Torr in a metal organic compound chemical vapor deposition device;
and sputtering a layer of silver on the gallium nitride layer by adopting a sputtering process under the conditions that the working temperature range is 100-300 ℃, the working pressure range is 1-5Pa and the sputtering power range is 10-50W in physical vapor deposition equipment to obtain the silver thin film layer.
10. The method of claim 9 wherein growing an electron blocking layer on the MQW layer further comprises:
before growing the gallium nitride layer, growing an aluminum gallium nitride layer on the multi-quantum well layer under the conditions that the growth temperature range is 850-1080 ℃ and the growth pressure range is 200-500 Torr in the metal organic compound chemical vapor deposition equipment.
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000164928A (en) * 1998-11-25 2000-06-16 Toshiba Electronic Engineering Corp Semiconductor light emitting device and its manufacture
CN103681996A (en) * 2013-10-17 2014-03-26 武汉光电工业技术研究院有限公司 UV (Ultraviolet) LED and preparation method thereof
CN104993026A (en) * 2015-05-19 2015-10-21 西安交通大学 Preparing method of single-chip GaN-based LED structure adjustable in color
CN108470803A (en) * 2018-03-20 2018-08-31 华灿光电（浙江）有限公司 A kind of epitaxial wafer and production method of light emitting diode
CN108598224A (en) * 2018-05-31 2018-09-28 华灿光电（浙江）有限公司 A kind of production method and its LED epitaxial slice of LED epitaxial slice
CN109346577A (en) * 2018-09-30 2019-02-15 华灿光电（浙江）有限公司 A kind of gallium nitride based LED epitaxial slice and preparation method thereof

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100736521B1 (en) * 2004-06-09 2007-07-06 삼성전자주식회사 Nanocrystal electroluminescence device and preparation method thereof
JP5197186B2 (en) * 2008-06-30 2013-05-15 株式会社東芝 Semiconductor light emitting device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000164928A (en) * 1998-11-25 2000-06-16 Toshiba Electronic Engineering Corp Semiconductor light emitting device and its manufacture
CN103681996A (en) * 2013-10-17 2014-03-26 武汉光电工业技术研究院有限公司 UV (Ultraviolet) LED and preparation method thereof
CN104993026A (en) * 2015-05-19 2015-10-21 西安交通大学 Preparing method of single-chip GaN-based LED structure adjustable in color
CN108470803A (en) * 2018-03-20 2018-08-31 华灿光电（浙江）有限公司 A kind of epitaxial wafer and production method of light emitting diode
CN108598224A (en) * 2018-05-31 2018-09-28 华灿光电（浙江）有限公司 A kind of production method and its LED epitaxial slice of LED epitaxial slice
CN109346577A (en) * 2018-09-30 2019-02-15 华灿光电（浙江）有限公司 A kind of gallium nitride based LED epitaxial slice and preparation method thereof

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