CN113284986A - Preparation method of light-emitting diode epitaxial wafer - Google Patents

Preparation method of light-emitting diode epitaxial wafer Download PDF

Info

Publication number
CN113284986A
CN113284986A CN202110330162.1A CN202110330162A CN113284986A CN 113284986 A CN113284986 A CN 113284986A CN 202110330162 A CN202110330162 A CN 202110330162A CN 113284986 A CN113284986 A CN 113284986A
Authority
CN
China
Prior art keywords
layer
well layer
ammonia gas
ingan
source
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.)
Granted
Application number
CN202110330162.1A
Other languages
Chinese (zh)
Other versions
CN113284986B (en
Inventor
王群
郭志琰
葛永晖
郭炳磊
董彬忠
李鹏
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
HC Semitek Zhejiang Co Ltd
Original Assignee
HC Semitek Zhejiang Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by HC Semitek Zhejiang Co Ltd filed Critical HC Semitek Zhejiang Co Ltd
Priority to CN202110330162.1A priority Critical patent/CN113284986B/en
Publication of CN113284986A publication Critical patent/CN113284986A/en
Application granted granted Critical
Publication of CN113284986B publication Critical patent/CN113284986B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier 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 with at least one potential-jump barrier or surface barrier 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
    • H01L33/0066—Processes for devices with an active region comprising only III-V compounds with a substrate not being a III-V compound
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices with at least one potential-jump barrier or surface barrier 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 with at least one potential-jump barrier or surface barrier 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 with at least one potential-jump barrier or surface barrier 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 with at least one potential-jump barrier or surface barrier 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 with at least one potential-jump barrier or surface barrier 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 with at least one potential-jump barrier or surface barrier 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 with at least one potential-jump barrier or surface barrier 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 with at least one potential-jump barrier or surface barrier 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 with at least one potential-jump barrier or surface barrier 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 system
    • H01L33/32—Materials of the light emitting region containing only elements of group III and group V of the periodic system containing nitrogen
    • H01L33/325—Materials of the light emitting region containing only elements of group III and group V of the periodic system containing nitrogen characterised by the doping materials
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Led Devices (AREA)

Abstract

The disclosure provides a preparation method of a light-emitting diode epitaxial wafer, and belongs to the technical field of light-emitting diodes. At least one InGaN well layer of the multiple quantum well layers is grown in accordance with a cyclic flow. The gallium source and the indium source in the organic metal source introduced into the reaction cavity can be uniformly paved on the GaN material, so that the crystal quality of the InGaN well layer is improved. And then, after the introduced ammonia gas of the well layer enters the reaction cavity, an InGaN film with uniform indium component distribution is formed on the GaN material, and the metal organic source and the ammonia gas of the well layer are alternately introduced into the reaction cavity, so that a plurality of InGaN films with uniform internal In component distribution can be sequentially stacked on the GaN material, and the InGaN well layer is obtained by stacking the plurality of InGaN films. The uniformity degree of In component distribution In the obtained InGaN well layer is improved, and the light emitting uniformity of the finally obtained light emitting diode can also be improved.

Description

Preparation method of light-emitting diode epitaxial wafer
Technical Field
The disclosure relates to the technical field of light emitting diodes, and particularly relates to a method for preparing a light emitting diode epitaxial wafer.
Background
The light emitting diode is a light emitting device with wide application, and is commonly used for communication signal lamps, automobile interior and exterior lamps, urban illumination, landscape illumination and the like. The light emitting diode epitaxial wafer is a basic structure for preparing a light emitting diode, and generally comprises a substrate and an n-type GaN layer, a multi-quantum well layer and a p-type GaN layer which are sequentially stacked on the substrate, wherein the multi-quantum well layer comprises a GaN barrier layer and an InGaN well layer which are alternately stacked.
When an InGaN well layer in the multi-quantum well layer grows, an organic metal source and ammonia gas in the well layer need to be introduced into a reaction cavity of epitaxial growth equipment at the same time for growing, wherein the organic metal source comprises a gallium source and an indium source. In the epitaxial wafer obtained by the method, lattice mismatch exists between the InGaN well layer and the n-type GaN layer or the GaN barrier layer, the defect occurs In the grown InGaN well layer due to the lattice mismatch, the situation that segregated clusters occur In the InGaN well layer due to the defect easily occurs, the distribution of In the InGaN well layer is uneven, and the light emitting uniformity of the finally obtained light emitting diode is reduced due to the uneven distribution of In the InGaN well layer.
Disclosure of Invention
The embodiment of the disclosure provides a preparation method of a light emitting diode epitaxial wafer, which can improve the light emitting efficiency and the light emitting uniformity of the light emitting diode epitaxial wafer. The technical scheme is as follows:
the embodiment of the disclosure provides a preparation method of a light emitting diode epitaxial wafer, which comprises the following steps:
providing a substrate;
growing an n-type GaN layer on the substrate;
alternately growing GaN barrier layers and InGaN well layers on the n-type GaN layer to form a multi-quantum well layer, at least one InGaN well layer in the multi-quantum well layer being grown according to a cyclic flow, the cyclic flow including:
alternately introducing a metal organic source and ammonia gas of the well layer into the reaction cavity until the InGaN well layer is formed, wherein the metal organic source comprises a gallium source and an indium source;
and growing a p-type GaN layer on the multi-quantum well layer.
Optionally, the ratio of the time length of the metal organic source introduced into the reaction chamber each time to the time length of the ammonia gas introduced into the well layer in the reaction chamber each time ranges from 1:1 to 1: 5.
Optionally, the time length of the well layer ammonia gas introduced into the reaction chamber each time ranges from 20 s to 60s, and the time length of the metal organic source introduced into the reaction chamber each time ranges from 2 s to 50 s.
Optionally, the loop process further includes:
and in the last time of continuously introducing ammonia gas into the well layer into the reaction cavity, introducing a gallium source into the reaction cavity.
Optionally, the loop process further includes:
and if the time length of introducing the ammonia gas of the well layer into the reaction cavity for the last time reaches the set time length which is 1/3-1/2 of the total time length of continuously introducing the ammonia gas of the well layer into the reaction cavity for the last time, introducing a gallium source into the reaction cavity until the InGaN well layer is formed.
Optionally, two InGaN well layers closest to the n-type GaN layer among the multiple quantum well layers are grown according to the cyclic flow.
Optionally, growing the GaN barrier layer in the multiple quantum well layer includes:
and introducing a gallium source with constant flow and barrier layer ammonia with variable flow into the reaction cavity until the GaN barrier layer is formed, wherein the flow of the barrier layer ammonia has a plurality of change cycles in the growth process of the GaN barrier layer, and the flow of the barrier layer ammonia is reduced and then increased in each change cycle.
Optionally, the maximum value of the flow of the barrier layer ammonia gas in each change period ranges from 60L/min to 140L/min, and the minimum value of the flow of the barrier layer ammonia gas in each change period ranges from 10L/min to 40L/min.
Optionally, the time length of each change period ranges from 5 s to 300 s.
Optionally, in each change cycle, a time period during which the flow rate of the barrier layer ammonia gas is decreased is equal to a time period during which the flow rate of the barrier layer ammonia gas is increased.
The beneficial effects brought by the technical scheme provided by the embodiment of the disclosure at least comprise:
the GaN barrier layers and the InGaN well layers are alternately grown on the n-type GaN layer to form a multi-quantum well layer, and at least one InGaN well layer of the multi-quantum well layer may be grown according to a cyclic flow. When the reaction cavity grows according to the circulation flow, the gallium source and the indium source in the organic metal source introduced into the reaction cavity can be uniformly paved on the GaN material, on one hand, the gallium source and the indium source paved and arranged on the GaN material can be compact, vacancy defects at the interface of part of the GaN material can be filled, part of the defects can be prevented from extending into the InGaN material, the internal defects of the InGaN well layer obtained by reaction are reduced, the crystal quality of the InGaN well layer is improved, and the light emitting efficiency of the light emitting diode can be improved. On the other hand, after the well layer ammonia gas introduced after the metal organic source enters the reaction cavity, the well layer ammonia gas reacts with the gallium source and the indium source which are uniformly layered on the GaN material, and an InGaN film with uniform indium component distribution is formed on the GaN material. And (3) alternately introducing a metal organic source and ammonia gas into the reaction cavity, so that a plurality of InGaN films with uniformly distributed In components can be sequentially stacked on the GaN material, and the InGaN well layer is obtained by stacking the plurality of InGaN films. The uniformity degree of In component distribution In the obtained InGaN well layer is improved, and the light emitting uniformity of the finally obtained light emitting diode can also be improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.
Fig. 1 is a flowchart of a method for manufacturing an epitaxial wafer of a light emitting diode according to an embodiment of the present disclosure;
fig. 2 is a schematic diagram illustrating a comparison of growth flow rates of a well layer and a barrier layer provided in an embodiment of the disclosure;
fig. 3 is a schematic structural diagram of an led epitaxial wafer according to an embodiment of the present disclosure;
fig. 4 is a flowchart of another method for manufacturing an epitaxial wafer of a light emitting diode according to an embodiment of the present disclosure;
fig. 5 is a schematic structural diagram of another light emitting diode epitaxial wafer according to an embodiment of the present disclosure.
Detailed Description
To make the objects, technical solutions and advantages of the present disclosure more apparent, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.
Fig. 1 is a flowchart of a method for manufacturing an led epitaxial wafer according to an embodiment of the present disclosure, and as shown in fig. 1, the method for manufacturing an led epitaxial wafer includes:
s101: a substrate is provided.
S102: an n-type GaN layer is grown on the substrate.
S103: and alternately growing the GaN barrier layers and the InGaN well layers on the n-type GaN layer to form a multi-quantum well layer, wherein at least one InGaN well layer in the multi-quantum well layer grows according to a cycle flow. A cyclic process comprising: and alternately introducing a metal organic source and ammonia gas of the well layer into the reaction cavity, wherein the metal organic source comprises a gallium source and an indium source until the InGaN well layer is formed.
The step S103 of alternately introducing the metal organic source and the ammonia gas into the reaction chamber may include: firstly introducing an organic metal source into the reaction cavity, wherein ammonia gas in a well layer is not introduced into the reaction cavity in the process of introducing the organic metal source; then introducing ammonia gas of a well layer into the reaction cavity, wherein an organic metal source is not introduced into the reaction cavity in the process of introducing the ammonia gas of the well layer; the flowing of the organic metal source without flowing the ammonia gas into the well layer and the flowing of the ammonia gas into the well layer without flowing the organic metal source in this stage are repeatedly performed.
It should be noted that "alternately introducing the metal organic source and the ammonia gas into the reaction chamber" in another implementation manner provided by the present disclosure may also include: alternatively, the ammonia gas in the well layer may be introduced into the reaction chamber without introducing the organometallic source, and then the two steps in this stage may be repeated.
S104: and growing a p-type GaN layer on the multi-quantum well layer.
The GaN barrier layers and the InGaN well layers are alternately grown on the n-type GaN layer to form a multi-quantum well layer, and at least one InGaN well layer of the multi-quantum well layer may be grown according to a cyclic flow. When the reaction cavity grows according to the circulation flow, the gallium source and the indium source in the organic metal source introduced into the reaction cavity can be uniformly paved on the GaN material, on one hand, the gallium source and the indium source paved and arranged on the GaN material can be compact, vacancy defects at the interface of part of the GaN material can be filled, part of the defects can be prevented from extending into the InGaN material, the internal defects of the InGaN well layer obtained by reaction are reduced, the crystal quality of the InGaN well layer is improved, and the light emitting efficiency of the light emitting diode can be improved. On the other hand, after the well layer ammonia gas introduced after the metal organic source enters the reaction cavity, the well layer ammonia gas reacts with the gallium source and the indium source which are uniformly layered on the GaN material, and an InGaN film with uniform indium component distribution is formed on the GaN material. And (3) alternately introducing a metal organic source and ammonia gas into the reaction cavity, so that a plurality of InGaN films with uniformly distributed In components can be sequentially stacked on the GaN material, and the InGaN well layer is obtained by stacking the plurality of InGaN films. The uniformity degree of In component distribution In the obtained InGaN well layer is improved, and the light emitting uniformity of the finally obtained light emitting diode can also be improved. The GaN material may be an n-type GaN layer or a GaN barrier layer. If the ammonia gas in the well layer is firstly introduced into the reaction cavity without introducing the organic metal source, and then the organic metal source is introduced without introducing the ammonia gas in the well layer. After the introduced ammonia gas in the well layer is uniformly distributed, the organic metal source introduced in the later step can be carried by the carrier gas, and reacts with the uniformly distributed ammonia gas in the well layer in the reaction cavity to generate a uniform InGaN material. And because the organic metal source has larger mass, most of the organic metal source still uniformly falls on the gallium nitride material In the process of introducing the organic metal source, vacancy defects at the interface of partial GaN material can be filled to prevent partial defects from extending into the InGaN material, and then most of the organic metal source slowly reacts with the uniformly distributed ammonia gas of the well layer to grow the InGaN film with more uniform In distribution.
If the number of defects existing inside the light emitting diode epitaxial wafer is too large, unstable In is likely to precipitate at the defects, and on the other hand, a part of carriers are trapped by the defects and recombination light emission is performed at the defects, and the number of carriers for normal recombination light emission In the multiple quantum well layer is reduced. Therefore, the defects in the LED epitaxial wafer are reduced, and the luminous efficiency of the LED is improved. In the prior art, when an organic metal source and ammonia gas In the well layer are introduced to grow the InGaN well layer, the gallium source In the organic metal source is easier to react with the ammonia gas In the well layer to generate a GaN material, In atoms are merged into the GaN material to form the InGaN material, the solid solution rate of the In atoms is low, the GaN material is formed too fast, and the In is easily distributed unevenly In the GaN material. Therefore, the metal organic source and the ammonia gas of the well layer are circularly and alternately introduced into the reaction cavity, and the ammonia gas of the well layer can also be uniformly reacted with the gallium source and the indium source to generate an InGaN material with uniform In distribution on the premise that the gallium source and the indium source are more uniformly distributed, so that the In precipitation and uneven distribution caused by the In solid solution rate can be reduced to a certain extent.
The nature of the well layer ammonia gas introduced in the InGaN well layer is ammonia gas, and the well layer ammonia gas is used only for name distinction.
Optionally, when the metal organic source and the ammonia gas in the well layer are introduced into the reaction chamber, the carrier gas used may be nitrogen gas. The metal organic source and the ammonia gas in the well layer can be stably brought into the reaction chamber, and the decomposition of the ammonia gas in the well layer can be inhibited to a certain extent.
In the circulation flow of step S103, the ratio of the time duration of the metal organic source introduced into the reaction chamber each time to the time duration of the well layer ammonia gas introduced into the reaction chamber each time ranges from 1:1 to 1: 5.
When the ratio of the time length of the metal organic source introduced into the reaction cavity to the time length of the well layer ammonia gas introduced into the reaction cavity is in the range, the well layer ammonia gas introduced subsequently has enough time to react with the gallium source and the indium source, and the finally obtained InGaN well layer can be guaranteed to have good quality.
Illustratively, the time duration of each time of introducing the metal organic source into the reaction chamber is equal, and the time duration of each time of introducing the ammonia gas into the well layer into the reaction chamber is also equal. The thickness of each obtained InGaN film is uniform, and the quality of an InGaN well layer obtained by laminating the finally obtained InGaN films is good.
Optionally, the time length of the well layer ammonia gas introduced into the reaction cavity each time ranges from 20 s to 60s, and the time length of the metal organic source introduced into the reaction cavity each time ranges from 2 s to 50 s.
The time length of the well layer ammonia gas introduced into the reaction cavity each time and the time length of the metal organic source introduced into the reaction cavity each time are respectively in the above ranges, the thicknesses of the gallium source and the indium source paved on the GaN material layer are reasonable, and the gallium source and the indium source can also fully react with the well layer ammonia gas introduced subsequently.
Illustratively, the flow of the gallium source introduced into the reaction cavity at each time ranges from 50 sccm to 200sccm, the flow of the indium source introduced into the reaction cavity synchronously with the gallium source at each time ranges from 500sccm to 1500sccm, and the flow of the well layer ammonia gas introduced into the reaction cavity at each time ranges from 50L/min to 120L/min. The InGaN well layer with good quality can be obtained through reaction.
For example, the cycle number of alternately introducing the metal organic source and the ammonia gas into the well layer into the reaction chamber may be 10 to 30. The thickness and the quality of the obtained InGaN well layer are good.
In step S103, when the ammonia gas in the well layer is introduced into the reaction chamber, the ammonia gas and the nitrogen gas in the well layer may be introduced into the reaction chamber at the same time, and the ratio of the sum of the flow rates of the ammonia gas and the nitrogen gas in the well layer to the flow rate of the nitrogen gas is 2 to 5.
The value range of the ratio of the sum of the flow rates of the nitrogen to the flow rate of the nitrogen is 2-5, the introduced nitrogen can effectively inhibit the decomposition of the ammonia gas In the well layer, and the nitrogen can ensure that the ammonia gas In the well layer can be carried to the position where the gallium source and the indium source are laid more uniformly, so that the InGaN material with more uniform In distribution is generated.
Optionally, when ammonia gas and nitrogen gas are simultaneously introduced into the well layer, the flow rate of the nitrogen gas ranges from 60L to 120L. The high-flow nitrogen can more uniformly carry the ammonia gas In the well layer to the position where the gallium source and the indium source are paved so as to generate the InGaN material with more uniform In distribution.
In step S103, the loop process may further include: and in the last time of continuously introducing ammonia gas into the well layer into the reaction cavity, introducing a gallium source into the reaction cavity.
When the InGaN well layer grows according to the circulation flow, the gallium source is introduced in the process of continuously introducing ammonia gas into the well layer for the last time, the proportion of gallium atoms and nitrogen atoms can be increased on one side close to the GaN barrier layer, the lattice constant of the InGaN material is enabled to be closer to the GaN material and to be transited to the GaN barrier layer, lattice mismatch between the InGaN well layer and the GaN barrier layer is reduced, and the crystal quality of the finally obtained multiple quantum well layer is improved so as to improve the light emitting efficiency.
Optionally, the loop process further includes: and if the time length of introducing the ammonia gas into the well layer for the last time reaches the set time length which is 1/3-1/2 of the total time length of continuously introducing the ammonia gas into the well layer for the last time, introducing the gallium source into the reaction chamber until the InGaN well layer is formed.
Well layer ammonia gas with set time length is firstly led in, the set time length is 1/3-1/2 of the total time length of the last continuous well layer ammonia gas led in the reaction cavity, the well layer ammonia gas reacts with the gallium source and the indium source to generate an InGaN material with certain thickness and in direct contact with the InGaN well layer, then the gallium source is led in, the proportion of gallium atoms and nitrogen atoms in the InGaN material is improved, the lattice constant of the last InGaN film is enabled to be closer to the GaN material, the transition to the GaN barrier layer is better, the lattice mismatch between the InGaN well layer and the GaN barrier layer is reduced, and the crystal quality of the finally obtained multi-quantum well layer is improved to improve the light emitting efficiency.
Illustratively, the loop flow further includes: and introducing a gallium source with the flow rate of 50-200sccm in the last process of continuously introducing the ammonia gas of the well layer into the reaction chamber until the InGaN well layer is formed.
And the gallium source with the flow rate within the above range is introduced in the process of introducing the ammonia gas into the well layer for the last time, so that the obtained final InGaN film has better quality, the good transition from the InGaN material to the GaN material can be realized, and the obtained multi-quantum well layer has better quality.
In step S103, two InGaN well layers closest to the n-type GaN layer among the multiple quantum well layers may be grown according to a cyclic flow.
Since there is a large lattice mismatch between the n-type GaN layer and the multiple quantum well layer, more defects are most likely to accumulate in the two InGaN well layers closest to the n-type GaN layer among the multiple quantum well layers. The two InGaN well layers closest to the n-type GaN layer in the multi-quantum well layer are grown according to the circulation process, so that the defects in the two InGaN well layers closest to the n-type GaN layer can be effectively reduced, the defects are prevented from extending into the subsequent InGaN well layers, and the overall crystal quality and the light emitting uniformity of the multi-quantum well layer are effectively improved.
In the implementation provided by the present disclosure, all InGaN well layers in the multiple quantum well layer or part of InGaN well layers in the multiple quantum well layer may also be grown according to a cyclic flow, which is not limited by the present disclosure.
In other implementations provided by the present disclosure, only two InGaN well layers closest to the n-type GaN layer among the multiple quantum well layers may be grown according to the cyclic flow, while the other InGaN well layers among the multiple quantum well layers are normally grown. The cost required by the growth of the multiple quantum well layer can be effectively controlled while the luminous efficiency and the luminous uniformity of the multiple quantum well layer can be effectively improved.
Note that the InGaN well layer is normally grown, and includes: and simultaneously and continuously introducing a gallium source, an indium source and ammonia gas of the well layer into the reaction cavity so as to obtain the InGaN well layer which normally grows on the GaN material.
In step S103, growing the GaN barrier layer may include:
and introducing a gallium source with constant flow and barrier layer ammonia with variable flow into the reaction cavity to form a GaN barrier layer, wherein the flow of the barrier layer ammonia has a plurality of change cycles, and the flow of the barrier layer ammonia is reduced and then increased in each change cycle.
In the process of forming the GaN barrier layer, when the flow of ammonia gas of the barrier layer is small, the concentration of a gallium source in the reaction cavity is high, so that the formation of vacancy defects corresponding to gallium of the GaN barrier layer can be inhibited, and when the flow of ammonia gas of the barrier layer is large, the concentration of nitrogen in the reaction cavity is high, so that the formation of vacancy defects corresponding to nitrogen of the GaN barrier layer can be inhibited. The flow of the layer barrier layer ammonia gas introduced into the reaction cavity is firstly reduced and then increased in each change period, so that vacancy defects corresponding to gallium and vacancy defects corresponding to nitrogen in the GaN barrier layer can be balanced, vacancy defects caused by atom vacancy finally existing in the GaN barrier layer are reduced, and the crystal quality of the GaN barrier layer is improved so as to finally improve the crystal quality of the multi-quantum well layer.
Optionally, the flow rate of the barrier layer ammonia gas can have n change cycles, and the sum of the time lengths of the n change cycles is equal to the growth time length of the GaN barrier layer. And the flow rate of the barrier layer ammonia gas corresponding to the last moment of the ith change period is the flow rate of the barrier layer ammonia gas corresponding to the starting moment of the i +1 change period. n and i are integers, n is greater than or equal to 3, i is greater than or equal to 1, and i is less than or equal to n-1. When the flow change of the ammonia gas in the barrier layer adopts the change rule in the section, vacancy defects generated in the GaN barrier layer are less, and the overall quality of the GaN barrier layer is better.
For example, the time duration corresponding to each variation period may be equal. And few vacancy defects can be generated in the GaN barrier layer.
Optionally, the time length of each change period ranges from 5 s to 300 s.
The duration of each change period is within the range, so that the increase of the defect of the inner space of the GaN barrier layer can be effectively inhibited, and the quality of the finally obtained GaN barrier layer is ensured to be better.
Illustratively, the time length of the flow rate decrease of the barrier layer ammonia gas is equal to the time length of the flow rate increase of the barrier layer ammonia gas in each change period. The increase of the defect of the inner space of the GaN barrier layer can be effectively inhibited, and the quality of the finally obtained GaN barrier layer is ensured to be better.
Optionally, in each change period, a decreasing change trend of the flow rate of the barrier layer ammonia gas and an increasing change trend of the flow rate of the barrier layer ammonia gas are in a mirror symmetry relationship. The increase of the defect of the inner space of the GaN barrier layer can be effectively inhibited.
In one implementation manner provided by the present disclosure, the ammonia gas in the inner barrier layer may be linearly decreased and linearly increased, or decreased and increased in a step shape in each period, which is not limited by the present disclosure.
Optionally, the maximum values of the ammonia gas in the corresponding barrier layers in the n change periods may be the same, and the minimum values of the ammonia gas in the corresponding barrier layers in the n change periods may be the same. The growth of the GaN barrier layer is convenient to control, and meanwhile, vacancy defects generated in the GaN barrier layer are fewer.
Optionally, the maximum value of the flow of the barrier layer ammonia gas in each change period ranges from 60L/min to 140L/min, and the minimum value of the flow of the barrier layer ammonia gas in each change period ranges from 10L/min to 40L/min.
When the value range of the maximum value and the value range of the minimum value of the barrier layer ammonia gas in each change period are respectively in the above ranges, vacancy defects caused by atom vacancy finally existing in the GaN barrier layer can be effectively reduced, the quality of the obtained GaN barrier layer is good, and the preparation cost of the light-emitting diode epitaxial wafer cannot be too high.
Illustratively, the maximum value of the flow of the barrier layer ammonia gas in each change period ranges from 100L/min to 130L/min, and the minimum value of the flow of the barrier layer ammonia gas in each change period ranges from 20L/min to 30L/min. The quality of the obtained GaN barrier layer is better.
It should be noted that the barrier layer ammonia gas and the well layer ammonia gas introduced when the InGaN well layer grows have the same structure and are both ammonia gas, and the barrier layer ammonia gas and the well layer ammonia gas are only used for name distinction.
To facilitate understanding, fig. 2 may be provided, where fig. 2 is a schematic diagram illustrating a comparison between growth flux of a well layer and a barrier layer provided in an embodiment of the present disclosure, and fig. 2 shows a variation of flux with time during growth of one InGaN well layer of a multiple quantum well layer and a GaN barrier layer adjacent to the InGaN well layer. The left side of the dotted line in fig. 2 is the growth flux of the InGaN well layer, the right side of the dotted line in fig. 2 is the growth flux of the GaN barrier layer, the horizontal axis is the time axis, and the vertical axis is the flux axis. Referring to fig. 2, the InGaN well layer grows according to a cyclic process, ammonia gas and the organic metal source are alternately introduced into the well layer, the flow rate of the gallium source corresponding to the GaN barrier layer is constant, and the ammonia gas in the well layer is present in a period of change that decreases and then increases.
In step S103, the growth temperature and growth pressure of the InGaN well layer may be 700-800 ℃ and 100-300 torr, respectively, and the growth temperature and growth pressure of the GaN barrier layer may be 700-900 ℃ and 100-300 torr, respectively. The obtained MQW layer has good quality.
Optionally, the thickness of the InGaN well layer is 2-4 nm, and the thickness of the GaN barrier layer is 5-10 nm. The obtained MQW layer has good quality.
Referring to fig. 3, fig. 3 is a schematic structural diagram of the light emitting diode epitaxial wafer obtained by performing step S104, and referring to fig. 3, the light emitting diode epitaxial wafer according to the embodiment of the present disclosure includes a substrate 1, and an n-type GaN layer 2, a multi-quantum well layer 3, and a p-type GaN layer 4 sequentially stacked on the substrate 1. The multiple quantum well layer 3 includes InGaN well layers 31 and GaN barrier layers 32 alternately stacked.
It should be noted that the structure of the light emitting diode epitaxial wafer provided in fig. 3 is only for illustration, and the method for preparing the light emitting diode epitaxial wafer shown in fig. 1 may also be applied to light emitting diode epitaxial wafers with other layers than the multiple quantum well layer 3, which are different from the layers shown in the previous paragraph, and the disclosure does not limit this.
Fig. 4 is a flowchart of another method for manufacturing an led epitaxial wafer according to an embodiment of the present disclosure, and as shown in fig. 4, the method for manufacturing an led epitaxial wafer includes:
s201: a substrate is provided.
Wherein the substrate may be a sapphire substrate. Easy to realize and manufacture.
Optionally, step S201 may further include: and treating the surface of the substrate for growing the epitaxial layer for 6-10 min under the conditions of hydrogen atmosphere and the temperature of the reaction cavity of 1000-1200 ℃. The impurity on the surface of the substrate can be reduced, and the quality of the epitaxial wafer of the light-emitting diode is ensured.
In one implementation mode provided by the present disclosure, the surface of the substrate for growing the epitaxial layer may also be processed for 8min under the conditions of hydrogen atmosphere and the temperature of the reaction chamber being 1100 ℃. The present disclosure is not so limited.
S202: a buffer layer is grown on a substrate.
Step S202 may include: and sequentially growing a GaN nucleating layer and an undoped GaN layer on the substrate. The growth temperature of the GaN nucleating layer is 450-600 ℃, and the pressure is 200-500 torr. The growth temperature of the non-doped GaN layer is 950-1200 ℃, and the growth pressure is controlled at 100-300 torr. The obtained buffer layer has better quality.
S203: and growing an n-type GaN layer on the GaN buffer layer.
Optionally, the growth temperature of the n-type GaN layer is 950-1200 ℃, and the growth pressure of the n-type GaN layer is 200-500 torr.
S204: and growing a multi-quantum well layer on the n-type GaN layer, wherein the multi-quantum well layer comprises a well layer and a GaN barrier layer which are alternately grown.
The step of growing the multiple quantum well layer can refer to the step of growing in step S103 in fig. 1, and thus is not described herein again.
S205: and growing a p-type GaN layer on the multi-quantum well layer.
Optionally, the growth pressure of the p-type GaN layer may be 100-300 torr, and the growth temperature of the p-type GaN layer may be 800-1000 ℃.
In one implementation provided by the present disclosure, the growth pressure of the p-type GaN layer may also be 200 torr. The present disclosure is not so limited.
Illustratively, the doping element in the p-type GaN layer is Mg, and the doping concentration of Mg is 1 × 1019～5*1019cm-3. The quality of the finally obtained p-type GaN layer is better.
S206: and growing a p-type contact layer on the p-type GaN layer.
Alternatively, the growth pressure of the p-type contact layer may be 100to 300Torr, and the growth temperature of the p-type contact layer may be 850 to 1050 ℃.
In one implementation provided by the present disclosure, the growth pressure of the p-type contact layer may be 200Torr and the growth temperature of the p-type contact layer may be 950 ℃. The present disclosure is not so limited.
S207: and annealing the light emitting diode epitaxial wafer.
The annealing can improve the quality of the epitaxial wafer of the light-emitting diode.
Optionally, the annealing temperature is 650-850 ℃ and the time duration is 5-15 minutes. The annealing effect is better.
In one implementation provided by the present disclosure, the temperature of the anneal may also be 750 ℃ and the duration may also be 10 minutes. The present disclosure is not so limited.
The method for manufacturing the light emitting diode epitaxial wafer shown in fig. 4 provides a more detailed method for growing the light emitting diode epitaxial wafer compared to the method for manufacturing the light emitting diode shown in fig. 1.
It should be noted that, in the embodiment of the present disclosure, the growth method of the light emitting diode is implemented according to VeecoK 465i or C4 or RB MOCVD (Metal Organic Chemical Vapor Deposition) equipment. According to high purity H2(Hydrogen) or high purity N2(Nitrogen) or high purity H2And high purity N2The mixed gas of (2) is used as a carrier gas, high-purity NH3As an N source, trimethyl gallium (TMGa) and triethyl gallium (TEGa) as gallium sources, trimethyl indium (TMIn) as indium sources, silane (SiH4) as an N-type dopant, trimethyl aluminum (TMAl) as an aluminum source, and magnesium dicylocene (CP)2Mg) as a P-type dopant.
The structure of the light emitting diode epitaxial wafer after step S207 is completed can be seen in fig. 5.
Fig. 5 is a schematic structural diagram of another light emitting diode epitaxial wafer according to an embodiment of the present disclosure, and as can be seen from fig. 5, in another implementation manner provided by the present disclosure, the light emitting diode epitaxial wafer may include a substrate 1, and a buffer layer 5, an n-type GaN layer 2, a multi-quantum well layer 3, a p-type GaN layer 4, and a p-type contact layer 6 grown on the substrate 1.
Alternatively, the buffer layer 5 includes a GaN nucleation layer 51 and an undoped GaN layer 52 sequentially stacked on the substrate 1. The thickness of the GaN nucleation layer 51 can be 10-30 nm, and the thickness of the undoped GaN layer 52 can be 1-3.5 μm. A good buffering effect can be achieved.
Alternatively, the doping element of the n-type GaN layer 2 may be Si, and the doping concentration of the Si element may be 1018～1020/cm3. The overall quality of the n-type GaN layer 2 is good.
Illustratively, the thickness of the n-type GaN layer 2 may be 2 to 3 μm. The obtained n-type GaN layer has good overall quality.
Alternatively, the p-type GaN layer 4 may be doped with Mg at a doping concentration of 1018/cm3～1020/cm3. The quality of the obtained p-type GaN layer 4 is good.
In one implementation provided by the present disclosure, the doping concentration of Mg in the p-type GaN layer 4 may also be 1019/cm3. The present disclosure is not so limited.
Illustratively, the thickness of the p-type contact layer 6 may be 15 nm.
Note that, in the epitaxial wafer structure shown in fig. 5, compared to the epitaxial wafer structure shown in fig. 3, a buffer layer 5 is added between the substrate 1 and the n-type GaN layer 2, and a p-type contact layer 6 is also grown on the p-type GaN layer 4. The obtained epitaxial wafer has better quality and luminous efficiency.
The invention is not to be considered as limited to the particular embodiments shown and described, but is to be understood that various modifications, equivalents, improvements and the like can be made without departing from the spirit and scope of the invention.

Claims (10)

1. A preparation method of a light emitting diode epitaxial wafer is characterized by comprising the following steps:
providing a substrate;
growing an n-type GaN layer on the substrate;
alternately growing GaN barrier layers and InGaN well layers on the n-type GaN layer to form a multi-quantum well layer, wherein at least one InGaN well layer in the multi-quantum well layer grows according to a cycle flow, and the cycle flow comprises the following steps:
alternately introducing a metal organic source and ammonia gas of the well layer into the reaction cavity, wherein the metal organic source comprises a gallium source and an indium source to form the InGaN well layer;
and growing a p-type GaN layer on the multi-quantum well layer.
2. The preparation method according to claim 1, wherein the ratio of the time duration of the metal organic source introduced into the reaction chamber to the time duration of the ammonia gas introduced into the well layer is 1:1 to 1: 5.
3. The preparation method according to claim 1, wherein the time duration of the well layer ammonia gas introduced into the reaction chamber each time is 20-60 s, and the time duration of the metal organic source introduced into the reaction chamber each time is 2-50 s.
4. The production method according to any one of claims 1 to 3, wherein the cyclic process further comprises:
and in the last process of continuously introducing ammonia gas into the well layer into the reaction cavity, introducing a gallium source into the reaction cavity.
5. The method of claim 4, wherein the recycling process further comprises:
and if the time length of introducing the ammonia gas of the well layer into the reaction cavity for the last time reaches the set time length which is 1/3-1/2 of the total time length of continuously introducing the ammonia gas of the well layer into the reaction cavity for the last time, introducing a gallium source into the reaction cavity until the InGaN well layer is formed.
6. The method according to any one of claims 1 to 3, wherein two of the InGaN well layers closest to the n-type GaN layer among the multiple quantum well layers are grown according to the cyclic flow.
7. The method according to any one of claims 1 to 3, wherein growing the GaN barrier layer comprises:
and introducing a gallium source with constant flow and barrier layer ammonia with variable flow into the reaction cavity to form the GaN barrier layer, wherein the flow of the barrier layer ammonia has a plurality of variation cycles, and the flow of the barrier layer ammonia is reduced and then increased in each variation cycle.
8. The preparation method of claim 7, wherein the maximum value of the flow rate of the barrier layer ammonia gas in each change period ranges from 60 to 140L/min, and the minimum value of the flow rate of the barrier layer ammonia gas in each change period ranges from 10 to 40L/min.
9. The preparation method according to claim 7, wherein the duration of each of the variation periods is in a range of 5 to 300 seconds.
10. The preparation method as claimed in claim 7, wherein the length of time that the flow rate of the barrier layer ammonia gas is decreased is equal to the length of time that the flow rate of the barrier layer ammonia gas is increased in each of the variation cycles.
CN202110330162.1A 2021-03-29 2021-03-29 Preparation method of light-emitting diode epitaxial wafer Active CN113284986B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110330162.1A CN113284986B (en) 2021-03-29 2021-03-29 Preparation method of light-emitting diode epitaxial wafer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110330162.1A CN113284986B (en) 2021-03-29 2021-03-29 Preparation method of light-emitting diode epitaxial wafer

Publications (2)

Publication Number Publication Date
CN113284986A true CN113284986A (en) 2021-08-20
CN113284986B CN113284986B (en) 2023-03-24

Family

ID=77276065

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110330162.1A Active CN113284986B (en) 2021-03-29 2021-03-29 Preparation method of light-emitting diode epitaxial wafer

Country Status (1)

Country Link
CN (1) CN113284986B (en)

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060157714A1 (en) * 2003-07-18 2006-07-20 Tae-Kyung Yoo Nitride semiconductor light emitting device
US20070221948A1 (en) * 2006-03-20 2007-09-27 Choi Rak J Group III nitride semiconductor thin film and group III semiconductor light emitting device
CN101937954A (en) * 2010-07-05 2011-01-05 扬州中科半导体照明有限公司 Epitaxial growth method for improving inner quantum efficiency of GaN-based LED
CN103695999A (en) * 2013-12-02 2014-04-02 中国电子科技集团公司第五十五研究所 Nitride single crystal membrane prepared by alternate source supply and method
CN104900778A (en) * 2015-05-18 2015-09-09 华灿光电(苏州）有限公司 Growing method of epitaxial wafer of light emitting diode and epitaxial wafer
CN109698123A (en) * 2017-10-24 2019-04-30 山东浪潮华光光电子股份有限公司 A kind of substrate etching method of GaAs base LED wafer
CN110148652A (en) * 2019-03-26 2019-08-20 华灿光电股份有限公司 The preparation method and epitaxial wafer of the epitaxial wafer of light emitting diode
CN110518096A (en) * 2019-07-05 2019-11-29 华灿光电(苏州）有限公司 The preparation method of LED epitaxial slice
CN111785817A (en) * 2020-08-25 2020-10-16 北京蓝海创芯智能科技有限公司 InGaN/(In) GaN quantum well structure and method for improving luminous uniformity of quantum well
CN112259647A (en) * 2020-09-08 2021-01-22 华灿光电（浙江）有限公司 Preparation method of light-emitting diode epitaxial wafer and light-emitting diode epitaxial wafer
CN112397622A (en) * 2021-01-20 2021-02-23 华灿光电（浙江）有限公司 Light emitting diode epitaxial wafer and preparation method thereof

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060157714A1 (en) * 2003-07-18 2006-07-20 Tae-Kyung Yoo Nitride semiconductor light emitting device
US20070221948A1 (en) * 2006-03-20 2007-09-27 Choi Rak J Group III nitride semiconductor thin film and group III semiconductor light emitting device
CN101937954A (en) * 2010-07-05 2011-01-05 扬州中科半导体照明有限公司 Epitaxial growth method for improving inner quantum efficiency of GaN-based LED
CN103695999A (en) * 2013-12-02 2014-04-02 中国电子科技集团公司第五十五研究所 Nitride single crystal membrane prepared by alternate source supply and method
CN104900778A (en) * 2015-05-18 2015-09-09 华灿光电(苏州）有限公司 Growing method of epitaxial wafer of light emitting diode and epitaxial wafer
CN109698123A (en) * 2017-10-24 2019-04-30 山东浪潮华光光电子股份有限公司 A kind of substrate etching method of GaAs base LED wafer
CN110148652A (en) * 2019-03-26 2019-08-20 华灿光电股份有限公司 The preparation method and epitaxial wafer of the epitaxial wafer of light emitting diode
CN110518096A (en) * 2019-07-05 2019-11-29 华灿光电(苏州）有限公司 The preparation method of LED epitaxial slice
CN111785817A (en) * 2020-08-25 2020-10-16 北京蓝海创芯智能科技有限公司 InGaN/(In) GaN quantum well structure and method for improving luminous uniformity of quantum well
CN112259647A (en) * 2020-09-08 2021-01-22 华灿光电（浙江）有限公司 Preparation method of light-emitting diode epitaxial wafer and light-emitting diode epitaxial wafer
CN112397622A (en) * 2021-01-20 2021-02-23 华灿光电（浙江）有限公司 Light emitting diode epitaxial wafer and preparation method thereof

Also Published As

Publication number Publication date
CN113284986B (en) 2023-03-24

Similar Documents

Publication Publication Date Title
CN109545924B (en) Light emitting diode epitaxial wafer and manufacturing method thereof
CN114864770A (en) Silicon-based gallium nitride epitaxial wafer and manufacturing method thereof
CN112397622B (en) Light emitting diode epitaxial wafer and preparation method thereof
CN112951963B (en) Light-emitting diode epitaxial wafer and preparation method thereof
CN112259647B (en) Preparation method of light-emitting diode epitaxial wafer and light-emitting diode epitaxial wafer
CN113644172A (en) Light emitting diode epitaxial wafer with insertion layer and preparation method thereof
CN114447170B (en) LED epitaxial wafer for improving light emitting uniformity and preparation method thereof
CN113644174B (en) Preparation method of light-emitting diode epitaxial wafer with p-type composite layer
CN113284996B (en) Light emitting diode epitaxial wafer and preparation method thereof
CN112864286B (en) Preparation method of light emitting diode epitaxial wafer
CN112864285B (en) Preparation method of light emitting diode epitaxial wafer
CN113284986B (en) Preparation method of light-emitting diode epitaxial wafer
CN113488567B (en) Light emitting diode epitaxial wafer with composite transition layer and preparation method thereof
CN113571607B (en) High-luminous-efficiency light-emitting diode epitaxial wafer and manufacturing method thereof
CN113113515B (en) Growth method of light emitting diode epitaxial wafer
CN113571615B (en) Light emitting diode epitaxial wafer for improving ohmic contact and manufacturing method thereof
CN111952419B (en) Preparation method of light-emitting diode epitaxial wafer
CN113193083B (en) Preparation method of light-emitting diode epitaxial wafer
CN114784150A (en) Epitaxial wafer of deep ultraviolet light-emitting diode and preparation method thereof
CN113161462A (en) Light emitting diode epitaxial wafer and manufacturing method thereof
CN114156380B (en) Light-emitting diode epitaxial wafer for improving internal quantum efficiency and preparation method thereof
CN113193087B (en) Preparation method of light emitting diode epitaxial wafer
CN113284987B (en) Preparation method of light-emitting diode epitaxial wafer
CN113284992B (en) Preparation method of light-emitting diode epitaxial wafer
CN112802933B (en) Light emitting diode epitaxial wafer and preparation method thereof

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