CN114566578A - Deep ultraviolet LED epitaxial wafer, preparation method and semiconductor device - Google Patents

Deep ultraviolet LED epitaxial wafer, preparation method and semiconductor device Download PDF

Info

Publication number
CN114566578A
CN114566578A CN202210326620.9A CN202210326620A CN114566578A CN 114566578 A CN114566578 A CN 114566578A CN 202210326620 A CN202210326620 A CN 202210326620A CN 114566578 A CN114566578 A CN 114566578A
Authority
CN
China
Prior art keywords
layer
baln
algan
quantum well
ultraviolet led
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.)
Pending
Application number
CN202210326620.9A
Other languages
Chinese (zh)
Inventor
韩娜
王国斌
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.)
Jiangsu Third Generation Semiconductor Research Institute Co Ltd
Original Assignee
Jiangsu Third Generation Semiconductor Research Institute 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 Jiangsu Third Generation Semiconductor Research Institute Co Ltd filed Critical Jiangsu Third Generation Semiconductor Research Institute Co Ltd
Priority to CN202210326620.9A priority Critical patent/CN114566578A/en
Publication of CN114566578A publication Critical patent/CN114566578A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—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
    • H01L33/14—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
    • H01L33/145—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure with a current-blocking structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/26—Materials of the light emitting region
    • H01L33/30—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table
    • H01L33/32—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table containing nitrogen
    • 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 invention discloses a deep ultraviolet LED epitaxial wafer, which comprises a nitride buffer layer, a nitride transition layer, an n-type nitride layer, a quantum well active layer, an electron barrier layer and a contact layer which are sequentially grown on a substrate; wherein the electron blocking layer is a BALN blocking layer; the quantum well active layer comprises a plurality of AlGaN quantum well layers/AlGaN quantum barrier layers which grow alternately, and the last quantum well structure is AlGaN/BALN. The invention utilizes the BAIN barrier layer to replace the conventional p-type AlGaN electronic barrier layer, can reduce the interface defect with a quantum well, and avoids the p-type doping problem of high Al component AlGaNEBL. Meanwhile, in order to further improve the wave function overlapping rate of the last quantum well, AlGaN/BALN is adopted in the last layer of quantum well, the wave function overlapping rate of the last layer of quantum well is improved, the electron hole wave functions in the active region of the quantum well are overlapped, the radiation recombination efficiency of the deep ultraviolet LED quantum well region is improved, and further the power and the efficiency of the deep ultraviolet LED are improved.

Description

Deep ultraviolet LED epitaxial wafer, preparation method and semiconductor device
Technical Field
The invention relates to the technical field of semiconductors, in particular to a deep ultraviolet LED epitaxial wafer, a preparation method and a semiconductor device.
Background
Currently, a deep-ultraviolet LED (Light-Emitting Diode) based on an AlGaN material attracts a wide attention in the industry due to its wide potential application in the fields of disinfection, air and water purification, biochemical detection, optical communication, and the like. However, the low external quantum efficiency of deep ultraviolet LEDs still does not meet the current application requirements, which is mainly limited by their low internal quantum efficiency and light extraction efficiency.
The quantum efficiency of the deep ultraviolet LED chip is low due to the following reasons: firstly, the epitaxial quality of the AlGaN material is not ideal enough, the defect density is high, the internal quantum efficiency is low, the electron blocking layer is mostly p-type AlGaN, but the AlGaN with high Al component has the problems of p-type doping and the like, and when the electron blocking layer of the traditional AlGaN blocks electrons, the high valence band step blocks the migration of holes to an active region, which affects the internal quantum luminous efficiency. Therefore, a new deep ultraviolet LED chip is needed to solve the above problems.
Disclosure of Invention
The invention aims to provide a deep ultraviolet LED epitaxial wafer which improves the drop effect and the luminous efficiency.
In order to solve the problems, the invention provides a deep ultraviolet LED epitaxial wafer, which comprises a nitride buffer layer, a nitride transition layer, an n-type nitride layer, a quantum well active layer, an electron barrier layer and a contact layer which are sequentially grown on a substrate;
wherein the electron blocking layer is a BALN blocking layer; the quantum well active layer comprises a plurality of AlGaN quantum well layers/AlGaN quantum barrier layers which grow alternately, and the last quantum well structure is AlGaN/BALN.
As a further development of the invention, the BAlN barrier layer comprises undoped BAlN.
As a further improvement of the invention, the device further comprises a BAlN coarsening layer, wherein the BAlN coarsening layer is positioned in front of the BAlN barrier layer; or the BAlN coarsening layer is a portion of the BAlN barrier layer.
As a further improvement of the invention, the thickness of the BAlN coarsening layer is 2nm-20 nm.
As a further improvement of the invention, when the BAlN rough layer is positioned in front of the BAlN barrier layer, the BAlN rough layer is grown between the final quantum well structure AlGaN/BAlN and the BAlN barrier layer.
As a further improvement of the invention, when the BAlN rough layer is positioned in front of the BAlN barrier layer, the BAlN rough layer is formed by coarsening a BAlN quantum barrier layer in the last layer of quantum well structure AlGaN/BAlN.
As a further improvement of the present invention, when the BAlN rough layer is a part of the BAlN barrier layer, the BAlN barrier layer includes a first barrier layer and a second barrier layer, the first barrier layer is the BAlN rough layer, and the second barrier layer is the BAlN non-rough layer; the thickness of the second barrier layer is larger than that of the first barrier layer, and the first barrier layer is located between the last layer of quantum well structure AlGaN/BAlN and the second barrier layer.
As a further improvement of the invention, the BALN quantum barrier layer in the last layer of quantum well structure AlGaN/BALN is doped with Si, and the doping concentration of the Si is not more than 1E18/CM3。
The invention also provides a preparation method of the deep ultraviolet LED epitaxial wafer, which is used for preparing the deep ultraviolet LED epitaxial wafer and comprises the following steps:
s1, growing a nitride buffer layer on the substrate;
s3, growing a nitride transition layer on the nitride buffer layer;
s4, growing an n-type nitride layer on the nitride transition layer;
s5, growing alternating AlGaN quantum well layers/AlGaN quantum barrier layers on the n-type nitride layer, and growing AlGaN/BALN layers as a last quantum well structure to form a quantum well active layer;
s6, growing a BAlN barrier layer on the last quantum well structure AlGaN/BAlN layer;
and S7, growing a contact layer on the BAlN barrier layer.
The invention also provides a semiconductor device which is characterized by comprising the deep ultraviolet LED epitaxial wafer.
The invention has the beneficial effects that:
according to the deep ultraviolet LED epitaxial wafer, the BAIN barrier layer is used for replacing a conventional p-type AlGaN electron barrier layer, so that the interface defect between the deep ultraviolet LED epitaxial wafer and a quantum well can be reduced, and the p-type doping problem of high Al component AlGaN EBL is avoided.
Meanwhile, the AlGaN/BALN is adopted in the last layer of quantum well, so that the wave function overlapping rate is improved compared with that of the existing AlGaN/AlGaN quantum well structure, the defect problem caused by the fact that an undoped BALN barrier layer replaces a highly-doped traditional AlGaN electron barrier layer is overcome, the radiation recombination efficiency of a deep ultraviolet LED quantum well region is improved, and further the power and the efficiency of a deep ultraviolet LED are improved.
The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.
Drawings
Fig. 1 is a structural diagram of a deep ultraviolet LED epitaxial wafer according to a first embodiment of the present invention;
FIG. 2 is a graph of electron leakage concentration for a conventional p-type AlGaN electron blocking layer at different doping concentrations;
FIG. 3 is a graph of electron leakage concentration for various doping concentrations of the BAlN barrier layer of the present invention;
FIG. 4 is a graph of internal quantum efficiency of a conventional p-type AlGaN electron blocking layer at different currents;
FIG. 5 is a graph of the internal quantum efficiency of the inventive BALN barrier at different currents;
fig. 6 is a structural diagram of a deep ultraviolet LED epitaxial wafer in the second embodiment of the present invention;
FIG. 7 is a graph of output power at different currents for different configurations;
FIG. 8 is a graph showing the wave function overlap ratio for the final quantum well structure using AlGaN/AlGaN, after replacing conventional p-AlGaN with BALN;
FIG. 9 is a graph showing the overlapping rate of wave functions according to a first embodiment of the present invention;
FIG. 10 shows the wave function overlapping rate in the third embodiment of the present invention;
FIG. 11 shows the overlapping rate of wave functions in the fifth embodiment of the present invention.
Description of the labeling:
10. a substrate; 20. a nitride buffer layer; 30. a nitride transition layer; 40. an n-type nitride layer; 50. a quantum well active layer; 51. AlGaN/BALN; 60. an electron blocking layer; 70. a contact layer; 80. BAlN coarsening layer.
Detailed Description
The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.
Example one
As shown in fig. 1, the present embodiment discloses a deep ultraviolet LED epitaxial wafer, which includes a nitride buffer layer 20, a nitride transition layer 30, an n-type nitride layer 40, a quantum well active layer 50, an electron blocking layer 60, and a contact layer 70, which are sequentially grown on a substrate 10;
wherein the electron blocking layer 60 is a BAlN blocking layer.
In the prior art, most of electron blocking layers are P-type AlGaN, but AlGaN with high Al component has the problems of P-type doping and the like, and the quantum luminous efficiency is improved by increasing the high doping of AlGaN in the prior art. Referring to fig. 2, the electron leakage concentration of the conventional p-type AlGaN electron blocking layer is different at different doping concentrations. It can be seen that the larger the Mg doping concentration is, the lower the electron leakage concentration is, and thus it is required to increase the Mg doping concentration to improve its ability to block electrons.
In this embodiment, a BAlN barrier layer is used, and experimental data show that: referring to fig. 3, the increase in the doping concentration of Mg does not increase its ability to block electrons. Therefore, the p-type doping problem of the AlGaN EBL with high Al component can be avoided by adopting the BALN as the barrier layer.
FIG. 4 is the internal quantum efficiency of a conventional p-type AlGaN electron blocking layer at different currents; figure 5 is the internal quantum efficiency of the inventive BAlN barrier at different currents. By comparing the data for the conventional p-type AlGaN electron blocking layer with the inventive BAlN blocking layer, it can be seen that for conventional p-type doped AlGaN. With the increase of Mg doping concentration, the difference of internal quantum efficiency is larger. For BAlN, the increase in doping concentration of Mg changes less to the internal quantum efficiency. Undoped or lowly doped BAlN can thus be used as electron blocking layer, wherein the electron leakage and the internal quantum efficiency through lowly doped BAlN and undoped BAlN do not differ much. Therefore, the BAlN barrier layer is not sensitive to the doping concentration, and the increase of the doping concentration cannot increase the electron blocking capability, whereas the traditional AlGaN electron barrier layer must be doped with high Mg to obtain a high-efficiency deep ultraviolet LED.
The BAlN barrier layer can replace a traditional AlGaN electron barrier layer to inhibit electron leakage, and probably because the valence band and the conduction band of the BAlN are lower than those of GaN by 0.2ev and higher than those of GaN by 2.1ev, the interface arrangement of the BAlN and the AlGaN is beneficial to electron conduction and hole injection.
In addition, when the device prepared by the undoped BALN barrier layer and the low-doped BALN barrier layer is compared, the undoped BALN barrier layer is found to have higher luminous intensity in the comparison of output power. Therefore, the invention adopts the undoped BALN barrier layer to replace the traditional AlGaN electron barrier layer with high doping. In the present embodiment, the quantum well active layer 50 includes a plurality of AlGaN quantum well layers/AlGaN quantum barrier layers alternately grown, and the final quantum well structure is AlGaN/BAlN 51.
According to the invention, after the undoped BALN barrier layer replaces the highly doped traditional AlGaN electron barrier layer, the wave function overlapping rate of the traditional AlGaN/AlGaN in the last quantum well structure is obviously reduced. Specifically, the last layer is the previous AlGaN/AlGaN quantum well structure, and the wave function overlapping rate of the previous AlGaN/AlGaN quantum well structure is between 41% and 42%, and the last layer is the AlGaN/AlGaN quantum well structure, and the wave function overlapping rate of the previous AlGaN/AlGaN quantum well structure is 32.99%, which is much lower than the wave function overlapping rate of the prior art, referring to fig. 8.
Referring to fig. 9, the AlGaN/BAlN is further adopted in the last quantum well structure, the wave function overlapping rate is increased to 35.73%, the wave function overlapping rate is increased compared with that of the conventional AlGaN/AlGaN quantum well structure, and the defect problem caused by the fact that a non-doped BAlN barrier layer replaces a highly-doped conventional AlGaN electron barrier layer is overcome.
Optionally, the substrate 10 is sapphire; the nitride buffer layer 20 is AlN; the nitride transition layer 30 is AlGaN; the n-type nitride layer 40 is an n-AlGaN layer; the contact layer 70 is AlN.
In the deep ultraviolet LED epitaxial wafer in the embodiment, the BAIN barrier layer is used for replacing a conventional p-type AlGaN electron barrier layer, so that the interface defect between the deep ultraviolet LED epitaxial wafer and a quantum well can be reduced, and the p-type doping problem of the high Al component AlGaN EBL is avoided. Meanwhile, the low-doped or undoped BAIN barrier layer has excellent electron leakage blocking capability and auxiliary hole injection capability, and greatly relieves the drop effect.
Meanwhile, the AlGaN/BALN is adopted in the last layer of quantum well structure, so that the wave function overlapping rate is improved compared with that of the traditional AlGaN/AlGaN quantum well structure, and the defect problem caused by the fact that a non-doped BALN barrier layer replaces a highly-doped traditional AlGaN electron barrier layer is overcome; the radiation recombination efficiency of the deep ultraviolet LED quantum well region is improved, and the power and the efficiency of the deep ultraviolet LED are further improved.
Example two
As shown in fig. 6, the present embodiment discloses a deep ultraviolet LED epitaxial wafer, which includes a nitride buffer layer 20, a nitride transition layer 30, an n-type nitride layer 40, a quantum well active layer 50, an electron blocking layer 60, and a contact layer 70, which are sequentially grown on a substrate 10;
wherein the electron blocking layer 60 is a BAlN blocking layer; the quantum well active layer 50 includes a plurality of AlGaN quantum well layers/AlGaN quantum barrier layers which are alternately grown, and the final quantum well structure is AlGaN/BAlN 51.
In this embodiment, the deep ultraviolet LED epitaxial wafer further includes a BAlN coarsening layer 80, where the BAlN coarsening layer 80 is located before the BAlN barrier layer, and the BAlN coarsening layer 80 is grown between the last quantum well structure AlGaN/BAlN and the BAlN barrier layer. The thickness of BAlN roughened layer 80 is preferably 2nm-5 nm.
Optionally, the BAlN barrier layer comprises undoped BAlN, and the problem of low overlap ratio of quantum well wavefunction occurs after the undoped BAIN barrier layer replaces p-AlGaN. And the last layer of quantum well adopts AlGaN/BALN, so that dislocation can be reduced, and after a coarsening layer is added, the stress of the quantum well structure and the electron barrier layer is reduced, so that electrons and a hole wave function are overlapped, thereby achieving two purposes.
Optionally, the substrate 10 is sapphire; the nitride buffer layer 20 is AlN; the nitride transition layer 30 is AlGaN; the n-type nitride layer 40 is an n-AlGaN layer; the contact layer 70 is AlN.
The BAlN coarsening layer 80 in this embodiment can increase the effective barrier height of electrons and reduce electron leakage. And after the roughening treatment of the BAlN roughened layer 80, the lateral expansion of electrons can be blocked, and the undoped BAlN electron blocking layer 60 is grown by growing the BAlN roughened layer 80 first, so that the surface stress of the BAlN electron blocking layer 60 can be reduced, and the surface appearance can be improved.
Fig. 7 is a graph of output power for different configurations at different currents. Wherein a is a traditional p-type AlGaN electron blocking layer; b is a low-doped BAlN barrier layer; c is the undoped BAlN barrier layer of example one; d is an undoped BAlN barrier layer with a BAlN roughening layer grown on the bottom in example two.
In the comparison of the output power, it can be found that the output power of the undoped BAlN is higher than that of the doped BAlN. The light emitting intensity of the undoped BAlN after the BAlN coarsening layer 80 is increased is higher, because the BAlN coarsening layer 80 stores electrons in the active region, the overflow problem of the electrons in the active region is further reduced.
EXAMPLE III
The embodiment discloses a deep ultraviolet LED epitaxial wafer, and as shown in fig. 6, the embodiment discloses a deep ultraviolet LED epitaxial wafer, which includes a nitride buffer layer 20, a nitride transition layer 30, an n-type nitride layer 40, a quantum well active layer 50, an electron blocking layer 60, and a contact layer 70, which are sequentially grown on a substrate 10;
wherein the electron blocking layer 60 is a BAlN blocking layer; the quantum well active layer 50 includes a plurality of AlGaN quantum well layers/AlGaN quantum barrier layers which are alternately grown, and the final quantum well structure is AlGaN/BAlN 51.
In this embodiment, the deep ultraviolet LED epitaxial wafer further includes a BAlN roughened layer, where the BAlN roughened layer is located before the BAlN barrier layer, and the BAlN roughened layer is formed by roughening a BAlN quantum barrier layer in a last layer of quantum well structure AlGaN/BAlN. Referring to fig. 10, in the third embodiment of the present invention, after the conventional p-AlGaN is replaced by the BAlN, the last quantum well in the AlGaN/AlGaN multiple quantum well is AlGaN/BAlN, and the overlap ratio of the roughened wave function is increased to 39.26%.
Optionally, the substrate 10 is sapphire; the nitride buffer layer 20 is AlN; the nitride transition layer 30 is AlGaN; the n-type nitride layer 40 is an n-AlGaN layer; the contact layer 70 is AlN.
Example four
The embodiment discloses a deep ultraviolet LED epitaxial wafer, and as shown in fig. 6, the embodiment discloses a deep ultraviolet LED epitaxial wafer, which includes a nitride buffer layer 20, a nitride transition layer 30, an n-type nitride layer 40, a quantum well active layer 50, an electron blocking layer 60, and a contact layer 70, which are sequentially grown on a substrate 10;
wherein the electron blocking layer 60 is a BAlN blocking layer; the quantum well active layer 50 includes a plurality of AlGaN quantum well layers/AlGaN quantum barrier layers which are alternately grown, and the final quantum well structure is AlGaN/BAlN 51.
In this embodiment, the deep ultraviolet LED epitaxial wafer further includes a BAlN roughened layer, where the BAlN roughened layer is a part of the BAlN barrier layer, the BAlN barrier layer includes a first barrier layer and a second barrier layer, the first barrier layer is the BAlN roughened layer, and the second barrier layer is a BAlN non-roughened layer; the thickness of the second barrier layer is larger than that of the first barrier layer, and the first barrier layer is located between the last layer of quantum well structure AlGaN/BAlN and the second barrier layer. The thickness of the BAlN roughened layer is preferably 1/4, preferably 2nm-20nm, of the BAlN barrier layer.
Compared with the first embodiment, in the present embodiment, a BAlN roughened layer is formed by roughening 1/4 a thickness below the original BAlN barrier layer, where the thickness of the roughened layer is smaller than that of the non-roughened layer. In the comparison of output power, it is found that the light emitting intensity can be further increased by roughening the lower part of the original BAlN barrier layer, and the roughened BAlN realizes the storage of electrons in the active region, so that the overflow problem of electrons in the active region is further reduced. Experiments show that the oversize thickness of the coarsened layer can affect the flatness of the epitaxial wafer and reduce the quality of the epitaxial wafer, and when the thickness of the BAlN coarsened layer is 1/4 which is less than or equal to the whole thickness of the BAlN barrier layer, the overflow of electrons in an active region can be further reduced on the premise of ensuring the quality of the epitaxial wafer.
Optionally, the substrate 10 is sapphire; the nitride buffer layer 20 is AlN; the nitride transition layer 30 is AlGaN; the n-type nitride layer 40 is an n-AlGaN layer; the contact layer 70 is AlN.
EXAMPLE five
The embodiment discloses a deep ultraviolet LED epitaxial wafer, and as shown in fig. 6, the embodiment discloses a deep ultraviolet LED epitaxial wafer, which includes a nitride buffer layer 20, a nitride transition layer 30, an n-type nitride layer 40, a quantum well active layer 50, an electron blocking layer 60, and a contact layer 70, which are sequentially grown on a substrate 10;
wherein the electron blocking layer 60 is a BAlN blocking layer; the quantum well active layer 50 includes a plurality of AlGaN quantum well layers/AlGaN quantum barrier layers which are alternately grown, and the final quantum well structure is AlGaN/BAlN 51.
In this embodiment, the deep ultraviolet LED epitaxial wafer further includes a BAlN roughened layer, where the BAlN roughened layer is located before the BAlN barrier layer, and the BAlN roughened layer is formed by roughening a BAlN quantum barrier layer in a last layer of quantum well structure AlGaN/BAlN.
Referring to fig. 11, after the BAlN replaces the conventional p-AlGaN, the last quantum well in the AlGaN/AlGaN multiple quantum well is AlGaN/BAlN, and after the last BAlN is roughened, the wave function overlapping rate is increased to 40.02% as compared with the first embodiment, and it is possible that when the roughened layer is located in the BAlN of the last quantum well structure, the stress of the quantum well structure and the electron blocking layer is reduced, so that the electron and hole wave functions overlap.
In addition, in the embodiment, the BAlN quantum barrier layer may be doped with Si, and the doping concentration of the Si is not more than 1E18/CM3. When the overlapping rate of the wave functions is 40.99%, the overlapping rate of the wave functions is obtained after doping Si. Probably because the reverse electric field generated by the silicon impurity activation can effectively shield the polarization electric field of the quantum barrier, the energy band inclination degree in the quantum well active region is reduced, the wave function overlapping rate of the current carrier in the quantum well is improved, the radiation recombination probability is improved, and the quantum efficiency in the deep ultraviolet LED is improved.
After the second, third and fourth embodiments are all BAlN instead of conventional p-AlGaN, the last quantum well in the AlGaN/AlGaN multi-quantum well is AlGaN/BAlN, a coarsening layer is provided and no Si is doped, and the wave function overlapping ratios of the last quantum well in the three embodiments, which is AlGaN/BAlN, are different from each other, and are all between the first embodiment and the fifth embodiment.
It can be seen that, after the traditional p-AlGaN is replaced by the BAlN, the wave function overlapping rate is improved when the AlGaN/BAlN is used as the last layer of quantum well structure compared with the case that the AlGaN/AlGaN is adopted as the last quantum well structure. The electron hole wave functions in the quantum well active region are overlapped, the radiation recombination efficiency of the deep ultraviolet LED quantum well region is improved, and further the power and the efficiency of the deep ultraviolet LED are improved.
Meanwhile, the BAlN quantum barrier layer in the last quantum well AlGaN/BAlN layer is coarsened, so that the wave function overlapping rate can be further improved. Further overcomes the defect problem caused by the fact that the undoped BALN barrier layer replaces the traditional AlGaN electron barrier layer with high doping.
And the BAlN quantum barrier layer in the last quantum well AlGaN/BAlN layer is coarsened and then doped with Si, so that the wave function overlapping rate can be further improved. The reverse electric field generated by the activation of the Si impurity can effectively shield the polarization electric field of the quantum barrier, so that the inclination degree of the energy band in the active region of the quantum well is reduced, the wave function overlapping rate of carriers in the quantum well is improved, the probability of radiation recombination is improved, and the quantum efficiency in the deep ultraviolet LED is improved.
EXAMPLE six
The embodiment discloses a preparation method of a deep ultraviolet LED epitaxial wafer, which is used for preparing the deep ultraviolet LED epitaxial wafer in the first embodiment and comprises the following steps:
s1, growing a nitride buffer layer on the substrate;
s3, growing a nitride transition layer on the nitride buffer layer;
s4, growing an n-type nitride layer on the nitride transition layer;
s5, growing alternating AlGaN quantum well layers/AlGaN quantum barrier layers on the n-type nitride layer, and growing AlGaN/BALN layers as a last quantum well structure to form a quantum well active layer;
s6, growing a BAlN barrier layer on the last quantum well structure AlGaN/BAlN layer;
and S7, growing a contact layer on the BAlN barrier layer.
EXAMPLE seven
The embodiment discloses a preparation method of a deep ultraviolet LED epitaxial wafer, which is used for preparing the deep ultraviolet LED epitaxial wafer described in the second embodiment and comprises the following steps:
s1, growing a nitride buffer layer on the substrate;
s3, growing a nitride transition layer on the nitride buffer layer;
s4, growing an n-type nitride layer on the nitride transition layer;
s5, growing alternating AlGaN quantum well layers/AlGaN quantum barrier layers on the n-type nitride layer, and growing AlGaN/BALN layers as a last quantum well structure to form a quantum well active layer;
s6, growing a BALN coarsening layer on the last quantum well structure AlGaN/BALN layer;
s7, growing a BAlN barrier layer on the BAlN coarsening layer;
s8, growing a contact layer on the BAlN barrier layer.
Example eight
The embodiment discloses a preparation method of a deep ultraviolet LED epitaxial wafer, which is used for preparing the deep ultraviolet LED epitaxial wafer in the third embodiment and comprises the following steps:
s1, growing a nitride buffer layer on the substrate;
s3, growing a nitride transition layer on the nitride buffer layer;
s4, growing an n-type nitride layer on the nitride transition layer;
s5, growing alternating AlGaN quantum well layers/AlGaN quantum barrier layers on the n-type nitride layer, and growing AlGaN/BALN layers as a last quantum well structure to form a quantum well active layer; coarsening the BALN quantum barrier layer in the last layer of quantum well AlGaN/BALN;
s6, growing a BAlN barrier layer on the last quantum well structure AlGaN/BAlN layer;
s7, growing a contact layer on the BAlN barrier layer.
Example nine
The embodiment discloses a preparation method of a deep ultraviolet LED epitaxial wafer, which is used for preparing the deep ultraviolet LED epitaxial wafer of the embodiment four and comprises the following steps:
s1, growing a nitride buffer layer on the substrate;
s3, growing a nitride transition layer on the nitride buffer layer;
s4, growing an n-type nitride layer on the nitride transition layer;
s5, growing alternating AlGaN quantum well layers/AlGaN quantum barrier layers on the n-type nitride layer, and growing AlGaN/BALN layers as a last quantum well structure to form a quantum well active layer;
s6, growing the first barrier layer on the last quantum well structure AlGaN/BALN layer;
s7, growing the second barrier layer on the first barrier layer;
s8, growing the contact layer on the second barrier layer.
EXAMPLE ten
The embodiment discloses a method for preparing a deep ultraviolet LED epitaxial wafer, which is used for preparing the deep ultraviolet LED epitaxial wafer in the fifth embodiment and comprises the following steps:
s1, growing a nitride buffer layer on the substrate;
s3, growing a nitride transition layer on the nitride buffer layer;
s4, growing an n-type nitride layer on the nitride transition layer;
s5, growing alternating AlGaN quantum well layers/AlGaN quantum barrier layers on the n-type nitride layer, and growing AlGaN/BALN layers as a last quantum well structure to form a quantum well active layer; coarsening a BAlN quantum barrier layer in the last layer of quantum well AlGaN/BAlN, and doping Si in the BAlN quantum barrier layer;
s6, growing a BAlN barrier layer on the last quantum well structure AlGaN/BAlN layer;
s7, growing a contact layer on the BAlN barrier layer.
EXAMPLE eleven
The embodiment discloses a semiconductor device which comprises the deep ultraviolet LED epitaxial wafer according to any one of the first embodiment to the fifth embodiment.
The above embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.

Claims (10)

1. The deep ultraviolet LED epitaxial wafer is characterized by comprising a nitride buffer layer, a nitride transition layer, an n-type nitride layer, a quantum well active layer, an electron barrier layer and a contact layer which are sequentially grown on a substrate;
wherein the electron blocking layer is a BALN blocking layer; the quantum well active layer comprises a plurality of AlGaN quantum well layers/AlGaN quantum barrier layers which grow alternately, and the last layer of quantum well structure is AlGaN/BALN.
2. The deep ultraviolet LED epitaxial wafer of claim 1, wherein the BAlN barrier layer comprises undoped BAlN.
3. The deep ultraviolet LED epitaxial wafer of claim 1, further comprising a BAlN roughening layer, the BAlN roughening layer located before the BAlN barrier layer; or the BAlN coarsening layer is a portion of the BAlN barrier layer.
4. The deep ultraviolet LED epitaxial wafer of claim 3, wherein the thickness of the BAlN roughened layer is 2nm-20 nm.
5. The deep ultraviolet LED epitaxial wafer of claim 3, wherein the BAlN coarsening layer is grown between the last quantum well structure AlGaN/BAlN and the BAlN barrier layer when the BAlN coarsening layer is before the BAlN barrier layer.
6. The deep ultraviolet LED epitaxial wafer of claim 3, wherein when the BAlN rough layer is located in front of the BAlN barrier layer, the BAlN rough layer is formed by roughening treatment of a BAlN quantum barrier layer in a last layer of quantum well structure AlGaN/BAlN.
7. The deep ultraviolet LED epitaxial wafer of claim 3, wherein when the BAlN roughening layer is part of the BAlN blocking layer, the BAlN blocking layer comprises a first blocking layer and a second blocking layer, the first blocking layer is a BAlN roughening layer, the second blocking layer is a BAlN non-roughening layer; the thickness of the second barrier layer is larger than that of the first barrier layer, and the first barrier layer is located between the last layer of quantum well structure AlGaN/BAlN and the second barrier layer.
8. The deep ultraviolet LED epitaxial wafer of claim 1, wherein a BAlN quantum barrier layer in the last quantum well structure AlGaN/BAlN is doped with Si, and the doping concentration of Si is not more than 1E18/CM3。
9. The preparation method of the deep ultraviolet LED epitaxial wafer is used for preparing the deep ultraviolet LED epitaxial wafer according to any one of claims 1 to 8, and comprises the following steps:
s1, growing a nitride buffer layer on the substrate;
s3, growing a nitride transition layer on the nitride buffer layer;
s4, growing an n-type nitride layer on the nitride transition layer;
s5, growing alternating AlGaN quantum well layer/AlGaN quantum barrier layer on the n-type nitride layer, and growing AlGaN/BALN layer as the last quantum well structure to form a quantum well active layer;
s6, growing a BAlN barrier layer on the last quantum well structure AlGaN/BAlN layer;
and S7, growing a contact layer on the BAlN barrier layer.
10. Semiconductor device, comprising a deep ultraviolet LED epitaxial wafer according to any one of claims 1 to 8.
CN202210326620.9A 2022-03-30 2022-03-30 Deep ultraviolet LED epitaxial wafer, preparation method and semiconductor device Pending CN114566578A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210326620.9A CN114566578A (en) 2022-03-30 2022-03-30 Deep ultraviolet LED epitaxial wafer, preparation method and semiconductor device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210326620.9A CN114566578A (en) 2022-03-30 2022-03-30 Deep ultraviolet LED epitaxial wafer, preparation method and semiconductor device

Publications (1)

Publication Number Publication Date
CN114566578A true CN114566578A (en) 2022-05-31

Family

ID=81720134

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210326620.9A Pending CN114566578A (en) 2022-03-30 2022-03-30 Deep ultraviolet LED epitaxial wafer, preparation method and semiconductor device

Country Status (1)

Country Link
CN (1) CN114566578A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115332408A (en) * 2022-10-18 2022-11-11 江西兆驰半导体有限公司 Deep ultraviolet LED epitaxial wafer, preparation method thereof and LED

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115332408A (en) * 2022-10-18 2022-11-11 江西兆驰半导体有限公司 Deep ultraviolet LED epitaxial wafer, preparation method thereof and LED
CN115332408B (en) * 2022-10-18 2023-01-31 江西兆驰半导体有限公司 Deep ultraviolet LED epitaxial wafer, preparation method thereof and LED

Similar Documents

Publication Publication Date Title
KR101174908B1 (en) Light-emitting device and manufacturing method thereof
JP2015046598A (en) Semiconductor light emitting device including hole injection layer, and method of manufacturing the same
KR100649496B1 (en) Nitride semiconductor light emitting device and method of manufacturing the same
CN116581214A (en) Light-emitting diode epitaxial wafer, preparation method thereof and light-emitting diode
CN113224214B (en) Red light emitting diode epitaxial wafer and preparation method thereof
CN109950371B (en) Ultraviolet LED epitaxial structure and preparation method thereof
KR100770440B1 (en) Nitride semiconductor light emitting device
CN112382710A (en) Deep ultraviolet LED with step-type electronic barrier layer structure and preparation method
CN114566578A (en) Deep ultraviolet LED epitaxial wafer, preparation method and semiconductor device
CN112366256B (en) Light emitting diode epitaxial wafer and manufacturing method thereof
CN109671817A (en) A kind of LED epitaxial slice and preparation method thereof
CN111261758B (en) Ultraviolet LED epitaxial structure and preparation method thereof
CN116014041B (en) Light-emitting diode epitaxial wafer, preparation method thereof and light-emitting diode
CN116314499B (en) Active barrier layer Mg-doped epitaxial structure, preparation method and chip
CN217641376U (en) LED epitaxial wafer and LED chip
CN116014045A (en) Light emitting diode with composite P-type layer and preparation method thereof
CN115966639A (en) Light emitting diode and preparation method thereof
CN214226936U (en) Semiconductor epitaxial structure and LED chip
CN111326622A (en) Light-emitting diode based on hole adjusting layer
CN110197861B (en) AlInGaN-based light-emitting diode
CN110993748B (en) Growth method of light emitting diode epitaxial wafer and light emitting diode epitaxial wafer
CN217544638U (en) LED electron barrier layer, LED epitaxial wafer and semiconductor device
CN111326616A (en) Semiconductor light-emitting element
CN111326618A (en) Semiconductor light emitting device capable of adjusting electron transfer rate
CN220121867U (en) LED epitaxial structure

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