CN113054063B - Ultraviolet light emitting diode, ultraviolet LED epitaxial layer structure and preparation method thereof - Google Patents

Ultraviolet light emitting diode, ultraviolet LED epitaxial layer structure and preparation method thereof Download PDF

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CN113054063B
CN113054063B CN202110154073.6A CN202110154073A CN113054063B CN 113054063 B CN113054063 B CN 113054063B CN 202110154073 A CN202110154073 A CN 202110154073A CN 113054063 B CN113054063 B CN 113054063B
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epitaxial layer
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ultraviolet led
contact layer
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CN113054063A (en
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郭炜
叶继春
徐厚强
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Ningbo Institute of Material Technology and Engineering of CAS
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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
    • H01L33/02—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
    • H01L33/005—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
    • 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
    • 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
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    • 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

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Abstract

The invention relates to the technical field of semiconductors, in particular to a light-emitting diode, an ultraviolet LED epitaxial layer structure and a preparation method thereof. The invention provides a preparation method of an ultraviolet LED epitaxial layer structure, which comprises the following steps: providing a nano patterned sapphire substrate with a c surface having a chamfer angle, wherein the chamfer angle is 0.5-8 degrees, and growing an AlN epitaxial layer and Al on the substrate in sequence x Ga 1‑x N epitaxial layer, N-Al y Ga 1‑y N contact layer, al m Ga 1‑m N/Al n Ga 1‑n N multiple quantum well active layer and p-type contact layer, wherein the p-type contact layer is p-Al g Ga 1‑g N/p-GaN superlattice contact layer, p-Al g Ga 1‑g At least one of the N contact layer and the p-GaN contact layer, wherein x is more than or equal to 0.5 and less than or equal to 1, y is more than or equal to 0.5 and less than or equal to 1, m is more than or equal to 0.3 and less than or equal to 0.7, N is more than or equal to 0.3 and less than or equal to 0.7, x is more than or equal to y, and m is more than or equal to N; g is more than or equal to 0.5 and less than or equal to 1. The preparation method can realize effective annihilation of dislocation, reduce dislocation density and promote the formation of carrier localization effect, thereby improving the luminous efficiency of the ultraviolet LED device. The invention also provides an ultraviolet light-emitting diode chip and an ultraviolet light-emitting diode.

Description

Ultraviolet light emitting diode, ultraviolet LED epitaxial layer structure and preparation method thereof
Technical Field
The invention relates to the technical field of semiconductors, in particular to an ultraviolet light emitting diode, an ultraviolet LED epitaxial layer structure and a preparation method thereof.
Background
Compared with the traditional light source, the ultraviolet light emitting diode (ultraviolet LED) solid-state light source based on the III-V group nitride material has the advantages of high efficiency, small volume, long service life and the like, thereby having wide application in the fields of illumination, display, curing and sterilization, communication, high-density storage and the like.
Due to the lack of large-size and low-cost nitride single crystal substrates, the III-V nitride films are all grown by heteroepitaxy. Among them, sapphire (Al) 2 O 3 ) Has the excellent properties of large size, low price, good light transmission, good chemical stability and thermal stability, and is the most used at presentIs a wide range of substrate materials. However, due to 16% lattice mismatch between the group III nitride and the sapphire, a large amount of dislocations and point defects are generated at the epitaxial interface, which affects the crystal quality of the thin film and reduces the performance of the ultraviolet LED and other optoelectronic devices. To solve this problem, patterned Sapphire Substrates (PSS) are commonly used to epitaxially grow GaN and InGaN. Through 3D nucleation and 2D growth, the PSS substrate can effectively relieve lattice mismatch at an interface and annihilate generated threading dislocation, so that the internal quantum efficiency and the luminous power of GaN-based and InGaN-based ultraviolet LED devices are improved. However, when AlN and high-aluminum-component AlGaN grow on the basis of the traditional PSS sapphire substrate, the defects that dislocation cannot be annihilated and the density is high still exist, and the transverse closing rate of the AlGaN growing AlN and high-aluminum components is slow, so that a smooth and high-quality thin film cannot be obtained. And because the chamfer angle of the prior sapphire substrate is generally 0-0.2 degrees, the quantum well has a uniform and straight interface, the phase separation of Al and Ga in AlGaN can not be caused, and the carrier localization effect can not be formed, thereby limiting the luminous efficiency of the ultraviolet LED device.
Disclosure of Invention
Based on the ultraviolet LED, the invention provides an ultraviolet LED, an ultraviolet LED epitaxial layer structure and a preparation method thereof. The preparation method provided by the invention realizes effective annihilation of dislocation, reduces dislocation density, and promotes formation of carrier localization effect, thereby improving luminous efficiency of the ultraviolet LED device.
On one hand, the invention provides a preparation method of an ultraviolet LED epitaxial layer structure, which comprises the following steps:
providing a nano patterned sapphire substrate with a chamfer angle on the c surface, wherein the chamfer angle is 0.5-8 degrees;
growing an AlN epitaxial layer on the substrate;
growing Al on the AlN epitaxial layer x Ga 1-x An N epitaxial layer;
in the presence of the Al x Ga 1-x Growing N-Al on N epitaxial layer y Ga 1-y An N contact layer;
in the n-Al y Ga 1-y Growing Al on N contact layer m Ga 1-m N/Al n Ga 1-n N multiple quantum well active layers; and
in the Al m Ga 1-m N/Al n Ga 1-n Growing a p-type contact layer on the N multi-quantum well active layer, wherein the p-type contact layer is p-Al g Ga 1-g N/p-GaN superlattice contact layer, p-Al g Ga 1-g At least one of an N contact layer and a p-GaN contact layer;
wherein x is more than or equal to 0.5 and less than or equal to 1, y is more than or equal to 0.5 and less than or equal to 1, m is more than or equal to 0.3 and less than or equal to 0.7, n is more than or equal to 0.3 and less than or equal to 0.7, and x is more than or equal to y and more than or equal to m and more than or equal to n; g is more than or equal to 0.5 and less than or equal to 1, and g is more than or equal to m.
In some embodiments, the chamfer angle is at an angle of 0.5 ° to 5 °.
In some embodiments, the nanopatterned structure is a pore structure, a segmental sphere structure, a pillar structure, an inverted pyramid structure, or a ladder structure.
In some embodiments, the AlN epitaxial layer has a thickness of 1 μm to 10 μm.
In some embodiments, the Al x Ga 1-x The thickness of the N epitaxial layer is 0.3-2 μm.
In some embodiments, the p-type contact layer has a thickness of 50nm to 500nm.
In some embodiments, the Al m Ga 1-m N/Al n Ga 1-n The N multi-quantum well active layer comprises 3-8 pairs of Al m Ga 1- m N/Al n Ga 1-n N。
In some embodiments, the Al m Ga 1-m N/Al n Ga 1-n The thickness of the N multiple quantum well active layer is 20 nm-150 nm.
In some embodiments, the Al is in the alloy m Ga 1-m N/Al n Ga 1-n Before the step of growing the p-type contact layer on the N multi-quantum well active layer, the method also comprises the step of growing a p-type electron blocking layer on the multi-quantum well active layer.
In another aspect of the present invention, an ultraviolet light emitting diode chip is further provided, which includes the epitaxial layer structure manufactured by the above method.
In another aspect of the present invention, there is further provided an ultraviolet light emitting diode, which includes the ultraviolet light emitting diode chip described above.
Has the advantages that:
according to the invention, researches show that in the process of preparing an ultraviolet LED epitaxial layer structure by using a traditional nano patterned substrate, when AlN or AlGaN with high-aluminum components is subjected to epitaxy, a large amount of threading dislocation exists and the AlN or AlGaN cannot be effectively annihilated; and the dislocation generated when the grain boundaries are combined can penetrate all the way to the surface of the thin film, so that the dislocation density is high, and the crystal quality is reduced. Therefore, the present invention performs epitaxy of AlGaN of AlN or high aluminum composition by using a nanopatterned sapphire substrate having a certain off-angle. The nano patterned substrate has the characteristics of small period and small folding area, and is favorable for high-quality epitaxy of AlN or AlGaN with high aluminum composition. Due to the existence of the oblique cutting angle, alN or AlGaN with high aluminum components has inconsistent transverse growth rate, so that a tilt crystal boundary with a certain angle is generated when crystals are combined, the oblique climbing of dislocation and defects is promoted, the annihilation of dislocation is finally realized, and the quality of the crystals is improved. And because the grain boundary is inclined, the vertical threading dislocation generated by the substrate can intersect with the inclined grain boundary to be effectively blocked, so that the dislocation density is further reduced, and the crystal quality is further improved.
Further, research shows that when the conventional sapphire substrate is used for preparing the epitaxial layer structure of the ultraviolet LED, because Al and Ga elements are completely dissolved, a carrier localization phenomenon cannot be generated, and thus, the luminous intensity of the ultraviolet LED cannot be effectively improved. In the process of preparing the ultraviolet LED epitaxial layer structure by using the substrate provided by the invention, the substrate is nano-patterned, so that the patterned period value can be freely adjusted, and the periodic multilayer quantum well structure is obtained. The multilayer quantum well can also generate abrupt change of components and thickness at the closed part of a crystal boundary, and then the uneven components and thickness generated by the high oblique cutting angle of the substrate are superposed, so that the formation of 'quantum dots' in a real sense is promoted, and the quantum luminous efficiency of the ultraviolet LED can be greatly improved.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a schematic illustration of the grain boundary and dislocation distribution produced when a nanopatterned sapphire substrate used in one embodiment of the present invention is epitaxially grown on an AlN layer;
fig. 2 is a schematic structural diagram of localized distribution of multiple quantum well active layers in an epitaxial layer structure of an ultraviolet LED fabricated in an embodiment of the present invention;
FIG. 3 is an AFM view of an AlN epitaxial layer in accordance with an embodiment of the invention;
fig. 4 is a graph showing the results of XRD test of the (002) plane and the (102) plane of the epitaxial AlN layer in example 4 and comparative example 1 of the present invention.
Detailed Description
Reference will now be made in detail to embodiments of the invention, one or more examples of which are described below. Each example is provided by way of explanation, not limitation, of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used on another embodiment to yield a still further embodiment.
It is therefore intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. Other objects, features and aspects of the present invention are disclosed in or are apparent from the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
In one aspect of the invention, a preparation method of an ultraviolet LED epitaxial layer structure is provided, which comprises the following steps:
providing a nano patterned sapphire substrate with a c surface having a chamfer angle, wherein the chamfer angle is 0.5-8 degrees;
growing an AlN epitaxial layer on a substrate;
growing Al on AlN epitaxial layer x Ga 1-x An N epitaxial layer;
in Al x Ga 1-x Growing N-Al on N epitaxial layer y Ga 1-y An N contact layer;
in n-Al y Ga 1-y Growing Al on the N contact layer m Ga 1-m N/Al n Ga 1-n N multiple quantum well active layers; and
in the presence of Al m Ga 1-m N/Al n Ga 1-n Growing a p-type contact layer on the N multi-quantum well active layer, wherein the p-type contact layer is p-Al g Ga 1-g N/p-GaN superlattice contact layer, p-Al g Ga 1-g At least one of an N contact layer and a p-GaN contact layer;
wherein x is more than or equal to 0.5 and less than or equal to 1, y is more than or equal to 0.5 and less than or equal to 1, m is more than or equal to 0.3 and less than or equal to 0.7, n is more than or equal to 0.3 and less than or equal to 0.7, and x is more than or equal to y and more than or equal to m and more than or equal to n; g is more than or equal to 0.5 and less than or equal to 1, and g is more than or equal to m.
As illustrated in fig. 1, a certain tilt angle θ exists during the epitaxial growth of the AlN layer 2 on the substrate 1 according to the present invention, which makes the AlN layer 2 have an inconsistent lateral growth rate. As shown in fig. 1, the growth rate of the AlN layer 2 on the right side is faster than that on the left side, so that a tilt grain boundary 3 having a certain angle is generated when the crystals merge, thereby promoting tilt climb of dislocations and defects, finally annihilating the dislocations, and improving the quality of the crystals. And threading dislocation generated at the top of the substrate 1 can intersect with the inclined grain boundary 3 to be effectively blocked, thereby further reducing the dislocation density.
Furthermore, the nano-patterned sapphire substrate is selected, so that the patterned period value can be freely adjusted, and the periodic multilayer quantum well can generate abrupt change of components and thickness at the closed part of a crystal boundary, thereby promoting the formation of 'quantum dots' in a real sense; and the growth of a step accumulation mode is realized by combining the regulation and control of the oblique angle, the enrichment of Ga at the edge of the step is accelerated, so that the phase separation of Ga-Al is realized, the formation of carrier localization is further realized, and the quantum luminous efficiency of the ultraviolet LED can be greatly improved.
In the present invention, the chamfer angle is an angle formed by inclining the c-plane toward the a-plane or the m-plane.
In some embodiments, the chamfer angle is 0.5 ° to 5 °, and may also be 1.5 °, 3 °, 4 °, 5.5 °, 6 °, 7 °.
In some embodiments, the nanopatterned structure may be a pore structure, a segmental sphere structure, a pillar structure, an inverted pyramid structure, or a ladder structure. Preferably, the nanopatterned structure may be selected from a pore structure or an inverted pyramid structure.
In some embodiments, the nanopatterned structure has a period Λ of 0.5 μm to 2 μm and a depth d of 0.05 μm to 1 μm.
In some embodiments, methods of making the uv LED epitaxial layer structures include, but are not limited to, metal Organic Chemical Vapor Deposition (MOCVD), molecular Beam Epitaxy (MBE), and Hydride Vapor Phase Epitaxy (HVPE).
In some embodiments, the AlN epitaxial layer has a thickness of 1 μm to 10 μm.
In some embodiments, al x Ga 1-x The thickness of the N epitaxial layer is 0.3-2 μm.
In some embodiments, the p-type contact layer has a thickness of 50nm to 500nm.
In some embodiments, al m Ga 1-m N/Al n Ga 1-n The N multi-quantum well active layer comprises 3-8 pairs of Al m Ga 1-m N/Al n Ga 1-n And N is added. In a preferred embodiment, al m Ga 1-m N/Al n Ga 1-n The N multi-quantum well active layer comprises 5 pairs of Al m Ga 1- m N/Al n Ga 1-n N。
In some embodiments, al m Ga 1-m N/Al n Ga 1-n The thickness of the N multiple quantum well active layer is 20 nm-150 nm.
In some embodiments, in Al m Ga 1-m N/Al n Ga 1-n Before the step of growing the p-type contact layer on the N multi-quantum well active layer, the method also comprises the step of growing a p-type electron blocking layer on the multi-quantum well active layer. The structure of the p-type electron blocking layer is not limited and may be selected from p-Al, for example x Ga 1-x N。
In some embodiments, the p-type electron blocking layer has a thickness of 15nm to 50nm.
In some embodiments, an electrode is also mounted on the p-type contact layer.
In another aspect of the present invention, an ultraviolet light emitting diode chip is further provided, which includes the epitaxial layer structure manufactured by the above method.
In another aspect of the present invention, there is further provided an ultraviolet light emitting diode, which includes the ultraviolet light emitting diode chip described above.
The ultraviolet light emitting diode, the ultraviolet LED epitaxial layer structure and the preparation method thereof according to the present invention are further described in detail below with reference to specific examples and comparative examples.
Example 1 preparation of ultraviolet LED epitaxial layer structure
(1) A 2-inch c-plane sapphire substrate is adopted, and a sapphire substrate with a c plane inclined by 0.5 degrees towards an m plane is manufactured through a cutting process;
(2) And (2) preparing the nano patterned sapphire substrate with the inverted pyramid structure on the sapphire substrate in the step (1) by a nano imprinting technology. The period of the nano graphical structure on the nano graphical sapphire substrate is 2 mu m, and the depth of the inverted pyramid structure is 1 mu m;
(3) Placing the nano-patterned sapphire substrate in the step (2) into an MOCVD device, and growing an AlN epitaxial layer with the thickness of 2 mu m and Al with the thickness of 800nm in sequence 0.7 Ga 0.3 N epitaxial layer, N-Al of 500nm thickness 0.65 Ga 0.35 N and 300nm thick N-Al 0.55 Ga 0.45 N, and further growing Al with a thickness of 80nm on the contact layer 0.6 Ga 0.4 N/Al 0.5 Ga 0.5 N multiple quantum well active layer comprising 5 pairs of Al 0.6 Ga 0.4 N/Al 0.5 Ga 0.5 And N is added. Then growing p-Al with the thickness of 300nm on the multiple quantum well active layer 0.6 Ga 0.4 And an N/p-GaN superlattice contact layer is formed, so that an ultraviolet LED epitaxial layer structure is manufactured. The rocking curve full width at half maximum of the (002) plane and the (102) plane of the epitaxial AlN layer was measured by XRD, and the results of the measurement are shown in table 1.
As shown in FIG. 2, because the step accumulation and the crystal boundary have a certain angle, the multi-quantum well active layer obtained based on the nano-patterning sapphire substrate epitaxy presents localized distribution, thereby realizing localized potential barrier and potential well and improving the radiation recombination efficiency of carriers.
Example 2 preparation of ultraviolet LED epitaxial layer structure
(1) Manufacturing a sapphire substrate with a c surface inclined by 2 degrees towards an a surface by adopting a 2-inch c-surface sapphire substrate through a cutting process;
(2) And (2) preparing the nano patterned sapphire substrate with the inverted pyramid structure on the sapphire substrate in the step (1) by a nano imprinting technology. The period of the nano graphical structure on the nano graphical sapphire substrate is 1 mu m, and the depth of the inverted pyramid structure is 500nm;
(3) Placing the nano-patterned sapphire substrate in the step (2) into an MOCVD device, and growing an AlN epitaxial layer with the thickness of 2 mu m and Al with the thickness of 800nm in sequence 0.8 Ga 0.2 N epitaxial layer, N-Al of 500nm thickness 0.65 Ga 0.35 N and 300nm thick N-Al 0.55 Ga 0.45 N, further growing Al with a thickness of 50nm on the contact layer 0.6 Ga 0.4 N/Al 0.5 Ga 0.5 An N multi-quantum well active layer comprising 3 pairs of Al 0.6 Ga 0.4 N/Al 0.5 Ga 0.5 And N is added. Then growing p-Al with the thickness of 300nm on the multiple quantum well active layer 0.6 Ga 0.4 And (3) an N/p-GaN superlattice contact layer, thereby preparing the ultraviolet LED epitaxial layer structure. The rocking curve full width at half maximum of the (002) plane and the (102) plane of the epitaxial AlN layer was measured by XRD, and the results of the measurement are shown in table 1.
Example 3 preparation of ultraviolet LED epitaxial layer structure
(1) Manufacturing a sapphire substrate with a c surface inclined by 4 degrees towards an a surface by a cutting process by adopting a 2-inch c-surface sapphire substrate;
(2) And (2) preparing the nano patterned sapphire substrate with the inverted pyramid structure on the sapphire substrate in the step (1) by a nano imprinting technology. The period of the nano graphical structure on the nano graphical sapphire substrate is 1 mu m, and the depth of the inverted pyramid structure is 500nm;
(3) Placing the nano-patterned sapphire substrate in the step (2) into an MOCVD device, and growing an AlN epitaxial layer with the thickness of 2 micrometers and Al with the thickness of 2 micrometers in sequence 0.8 Ga 0.2 N epitaxial layer, N-Al with thickness of 500nm 0.65 Ga 0.35 N and 300nm thick N-Al 0.55 Ga 0.45 N, further growing Al with a thickness of 60nm on the contact layer 0.6 Ga 0.4 N/Al 0.5 Ga 0.5 N multiple quantum well active layer comprising 5 pairs of Al 0.6 Ga 0.4 N/Al 0.5 Ga 0.5 And N is added. Then growing p-Al with the thickness of 300nm on the multiple quantum well active layer 0.6 Ga 0.4 And (3) an N/p-GaN superlattice contact layer, thereby preparing the ultraviolet LED epitaxial layer structure. The rocking curve full width at half maximum of the (002) plane and the (102) plane of the epitaxial AlN layer was measured by XRD, and the results of the measurement are shown in table 1.
Example 4 preparation of ultraviolet LED epitaxial layer structure
(1) Manufacturing a sapphire substrate with a c surface inclined by 5 degrees towards an m surface by adopting a 2-inch c-surface sapphire substrate through a cutting process;
(2) And (2) preparing the nano patterned sapphire substrate with the hole-shaped structure on the sapphire substrate obtained in the step (1) by a nano imprinting technology. The period of the nano patterned structure on the nano patterned sapphire substrate is 500nm, the upper aperture is 400nm, the lower aperture is 100nm, and the aperture depth is 50nm;
(3) Placing the nano-patterned sapphire substrate in the step (2) into an MOCVD device, and growing an AlN epitaxial layer with the thickness of 3 mu m and Al with the thickness of 800nm in sequence 0.65 Ga 0.35 N epitaxial layer, N-Al with thickness of 500nm 0.65 Ga 0.35 N and 300nm thick N-Al 0.55 Ga 0.45 N, further growing Al on the contact layer with a thickness of 100nm 0.6 Ga 0.4 N/Al 0.5 Ga 0.5 N multiple quantum well active layer comprising 5 pairs of Al 0.6 Ga 0.4 N/Al 0.5 Ga 0.5 And N is added. Then growing p-Al with the thickness of 300nm on the multiple quantum well active layer 0.6 Ga 0.4 And an N/p-GaN superlattice contact layer is formed, so that an ultraviolet LED epitaxial layer structure is manufactured. The rocking curve full width at half maximum of the (002) plane and the (102) plane of the epitaxial AlN layer was measured by XRD, and the results of the measurement are shown in table 1.
Example 5 preparation of ultraviolet LED epitaxial layer structure
(1) Manufacturing a sapphire substrate with a c surface inclined by 6 degrees towards an m surface by adopting a 2-inch c-surface sapphire substrate through a cutting process;
(2) And (2) preparing the nano patterned sapphire substrate with the inverted pyramid structure on the sapphire substrate in the step (1) by a nano imprinting technology. The period of the nano graphical structure on the nano graphical sapphire substrate is 2 mu m, and the depth of the inverted pyramid structure is 1 mu m;
(3) Placing the nano-patterned sapphire substrate in the step (2) into an MOCVD device, and growing an AlN epitaxial layer with the thickness of 5 mu m and Al with the thickness of 800nm in sequence 0.65 Ga 0.35 N epitaxial layer, N-Al of 500nm thickness 0.65 Ga 0.35 N and 300nm thick N-Al 0.55 Ga 0.45 N, further growing Al with a thickness of 100nm on the contact layer 0.6 Ga 0.4 N/Al 0.5 Ga 0.5 N multiple quantum well active layer comprising 8 pairs of Al 0.6 Ga 0.4 N/Al 0.5 Ga 0.5 And N is added. Then growing p-Al with the thickness of 300nm on the multiple quantum well active layer 0.6 Ga 0.4 And (3) an N/p-GaN superlattice contact layer, thereby preparing the ultraviolet LED epitaxial layer structure. The rocking curve full width at half maximum of the (002) plane and the (102) plane of the epitaxial AlN layer was measured by XRD, and the results of the measurement are shown in table 1.
Example 6 preparation of ultraviolet LED epitaxial layer structure
(1) Manufacturing a sapphire substrate with a c surface inclined by 8 degrees towards an m surface by adopting a 2-inch c-surface sapphire substrate through a cutting process;
(2) And (2) preparing the nano patterned sapphire substrate with the hole-shaped structure on the sapphire substrate obtained in the step (1) by a nano imprinting technology. The period of the nano graphical structure on the nano graphical sapphire substrate is 2 mu m, and the aperture depth is 1 mu m;
(3) Placing the nano-patterned sapphire substrate in the step (2) into an MOCVD device, and growing an AlN epitaxial layer with the thickness of 1 mu m and Al with the thickness of 500nm in sequence 0.6 Ga 0.4 N epitaxial layer, N-Al of 500nm thickness 0.6 Ga 0.4 And an N contact layer. Then, the MBE technology is utilized to epitaxially grow Al with the thickness of 60nm on the contact layer 0.55 Ga 0.45 N/Al 0.45 Ga 0.55 N multiple quantum well active layer comprising 5 pairs of Al 0.55 Ga 0.45 N/Al 0.45 Ga 0.55 N, then sequentially epitaxially growing p-Al with the thickness of 30nm on the multiple quantum well active layer 0.6 Ga 0.4 N-electron blocking layer, 200nm thick p-Al 0.5 Ga 0.5 N and p-GaN with the thickness of 50nm jointly form a contact layer, so that the ultraviolet LED epitaxial layer structure is manufactured. The rocking curve full width at half maximum of the (002) plane and the (102) plane of the epitaxial AlN layer was measured by XRD, and the results are shown in table 1. The morphology of the epitaxial AlN layer is shown in fig. 3. The epitaxial AlN layer surface roughness RMS was found by calculation to be 1.7nm, indicating a significant step-accumulation growth mode.
Comparative example 1 preparation of ultraviolet LED epitaxial layer structure
Comparative example 1 was prepared substantially the same as example 4, except that: the chamfer angle of the nanopatterned sapphire substrate was 0.2 °.
(1) And preparing the nano patterned sapphire substrate with the porous structure on the 2-inch c-plane sapphire substrate by using a nano imprinting technology. The period of the nano-patterned sapphire substrate is 500nm, the upper aperture is 400nm, the lower aperture is 100nm, and the aperture depth is 50nm;
(2) Placing the nano-patterned sapphire substrate in the step (1) in an MOCVD device, and growing an AlN epitaxial layer with the thickness of 3 mu m and Al with the thickness of 800nm in sequence 0.65 Ga 0.35 N epitaxial layer, N-Al of 500nm thickness 0.65 Ga 0.35 N and 300nm thick N-Al 0.55 Ga 0.45 N, further growing Al on the contact layer with a thickness of 100nm 0.6 Ga 0.4 N/Al 0.5 Ga 0.5 N multiple quantum well active layer comprising 5 pairs of Al 0.6 Ga 0.4 N/Al 0.5 Ga 0.5 And N is added. Then growing p-Al with the thickness of 300nm on the multiple quantum well active layer 0.6 Ga 0.4 And an N/p-GaN superlattice contact layer. The rocking curve full width at half maximum of the (002) plane and the (102) plane of the epitaxial AlN layer was measured by XRD, and the results of the measurement are shown in table 1.
Fig. 4 is a rocking curve graph obtained by XRD tests of the (002) plane and the (102) plane of the epitaxial AlN layer in example 4 and comparative example 1, and it is understood from the graphs that the peak profiles of the rocking curves of the (002) plane and the (102) plane of the epitaxial AlN layer produced in example 4 are both sharp as compared with the peak profile of comparative example 1, indicating that the rocking curves of the (002) plane and the (102) plane of the epitaxial AlN layer produced in example 4 are both low in full width at half maximum, i.e., low in dislocation density.
Comparative example 2 preparation of ultraviolet LED epitaxial layer structure
Comparative example 2 was prepared substantially the same as example 4, except that: the substrate used was a high bevel angle planar sapphire substrate.
(1) Selecting a 2-inch c-plane sapphire substrate, and manufacturing a sapphire substrate with a c plane inclined by 5 degrees towards an m plane through a cutting process;
(2) Placing the nano-patterned sapphire substrate in the step (1) in an MOCVD device, and growing an AlN epitaxial layer with the thickness of 3 mu m and Al with the thickness of 800nm in sequence 0.65 Ga 0.35 N epitaxial layer, N-Al of 500nm thickness 0.65 Ga 0.35 N and 300nm thick N-Al 0.55 Ga 0.45 N, further growing Al on the contact layer with a thickness of 100nm 0.6 Ga 0.4 N/Al 0.5 Ga 0.5 N multiple quantum well active layer comprising 5 pairs of Al 0.6 Ga 0.4 N/Al 0.5 Ga 0.5 And N is added. Then growing p-Al with the thickness of 300nm on the multiple quantum well active layer 0.6 Ga 0.4 And an N/p-GaN superlattice contact layer. The rocking curve full width at half maximum of the (002) plane and the (102) plane of the epitaxial AlN layer was measured by XRD, and the results of the measurement are shown in table 1.
TABLE 1 rocking curve full width at half maximum of (002) and (102) planes of epitaxial AlN layer
Figure BDA0002933861610000131
By analyzing the data of example 4 of the present invention and comparative example 1, it can be understood that the chamfer angle is not properly controlled. Even the use of a nanopatterned sapphire substrate does not effectively reduce the dislocation density of the epitaxial AlN layer. Analysis of the test data of example 4 and comparative example 2, however, shows that effective dislocation density reduction is also difficult to achieve without the use of nanopatterned sapphire substrates, despite the appropriate chamfer angle. Namely, the invention can reduce the dislocation density and improve the crystal quality by selecting the nano-patterned sapphire substrate epitaxial AlN layer with a certain chamfer angle.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that various changes and modifications can be made by those skilled in the art without departing from the spirit of the invention, and these changes and modifications are all within the scope of the invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A preparation method of an ultraviolet LED epitaxial layer structure is characterized by comprising the following steps:
providing a nano patterned sapphire substrate with a c surface having a chamfer angle, wherein the chamfer angle is 0.5-5 degrees;
growing an AlN epitaxial layer on the substrate;
growing Al on the AlN epitaxial layer x Ga 1-x An N epitaxial layer;
in the presence of the Al x Ga 1-x Growing N-Al on N epitaxial layer y Ga 1-y An N contact layer;
in the n-Al y Ga 1-y Growing Al on N contact layer m Ga 1-m N/Al n Ga 1-n N multiple quantum well active layers; and
in the Al m Ga 1-m N/Al n Ga 1-n Growing a p-type contact layer on the N multi-quantum well active layer, wherein the p-type contact layer is p-Al g Ga 1-g N/p-GaN superlattice contact layer, p-Al g Ga 1-g At least one of an N contact layer and a p-GaN contact layer;
wherein x is more than or equal to 0.5 and less than or equal to 1, y is more than or equal to 0.5 and less than or equal to 1, m is more than or equal to 0.3 and less than or equal to 0.7, n is more than or equal to 0.3 and less than or equal to 0.7, x is more than or equal to y, and m is more than or equal to n; g is more than or equal to 0.5 and less than or equal to 1.
2. The method for preparing the ultraviolet LED epitaxial layer structure according to claim 1, wherein the nano-patterned structure is a hole structure, a truncated sphere structure, a columnar structure, an inverted pyramid structure or a ladder structure.
3. The method for preparing an epitaxial layer structure of an ultraviolet LED according to claim 1, wherein the AlN epitaxial layer has a thickness of 1 μm to 10 μm.
4. The method for preparing an epitaxial layer structure of an ultraviolet LED according to claim 1, wherein the Al is x Ga 1-x The thickness of the N epitaxial layer is 0.3-2 μm.
5. The method for preparing the epitaxial layer structure of the ultraviolet LED according to claim 1, wherein the p-type contact layer has a thickness of 50nm to 500nm.
6. The method for preparing an epitaxial layer structure of an ultraviolet LED according to claim 1, wherein the Al is m Ga 1-m N/Al n Ga 1-n The N multi-quantum well active layer comprises 3-8 pairs of Al m Ga 1-m N/Al n Ga 1-n N。
7. The method for preparing an epitaxial layer structure of an ultraviolet LED according to claim 1, wherein the Al is m Ga 1-m N/Al n Ga 1-n The thickness of the N multi-quantum well active layer is 20 nm-150 nm.
8. The method for preparing an epitaxial layer structure of an ultraviolet LED according to any one of claims 1 to 7, wherein Al is added to the epitaxial layer structure m Ga 1-m N/Al n Ga 1-n Before the step of growing the p-type contact layer on the N multi-quantum well active layer, the method also comprises the step of growing a p-type electron blocking layer on the multi-quantum well active layer.
9. An ultraviolet light emitting diode chip, comprising an epitaxial layer structure prepared by the method of any one of claims 1 to 8.
10. An ultraviolet light-emitting diode comprising the ultraviolet light-emitting diode chip as claimed in claim 9.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102332515A (en) * 2011-09-16 2012-01-25 协鑫光电科技（张家港）有限公司 LED (light-emitting diode) and manufacturing method thereof
JP2013173641A (en) * 2012-02-24 2013-09-05 Tokuyama Corp Gallium nitride crystal laminated substrate and method for manufacturing the same
CN110571311A (en) * 2019-07-30 2019-12-13 中国科学技术大学 multi-quantum well structure, photoelectric device epitaxial wafer and photoelectric device
CN112151645A (en) * 2020-09-16 2020-12-29 西安电子科技大学 Preparation of large-angle oblique-cutting sapphire substrate AlN, light-emitting diode and preparation method thereof

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* Cited by examiner, † Cited by third party
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TWI565094B (en) * 2012-11-15 2017-01-01 財團法人工業技術研究院 Nitride semiconductor device
EP3293774B1 (en) * 2015-07-21 2020-03-18 Soko Kagaku Co., Ltd. Nitride semiconductor ultraviolet light-emitting element
WO2018217973A1 (en) * 2017-05-26 2018-11-29 Yale University Nitrogen-polar and semipolar gan layers and devices formed on sapphire with a high-temperature a1n buffer

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102332515A (en) * 2011-09-16 2012-01-25 协鑫光电科技（张家港）有限公司 LED (light-emitting diode) and manufacturing method thereof
JP2013173641A (en) * 2012-02-24 2013-09-05 Tokuyama Corp Gallium nitride crystal laminated substrate and method for manufacturing the same
CN110571311A (en) * 2019-07-30 2019-12-13 中国科学技术大学 multi-quantum well structure, photoelectric device epitaxial wafer and photoelectric device
CN112151645A (en) * 2020-09-16 2020-12-29 西安电子科技大学 Preparation of large-angle oblique-cutting sapphire substrate AlN, light-emitting diode and preparation method thereof

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