CN115458651A - Green light emitting diode epitaxial wafer, preparation method thereof and green light emitting diode - Google Patents
Green light emitting diode epitaxial wafer, preparation method thereof and green light emitting diode Download PDFInfo
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- 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
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- 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
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- H01L33/26—Materials of the light emitting region
- H01L33/30—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table
- H01L33/32—Materials of the light emitting region containing only elements of Group III and Group V of the Periodic Table containing nitrogen
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Abstract
The invention discloses a green light emitting diode epitaxial wafer, a preparation method thereof and a green light emitting diode, and relates to the field of semiconductor photoelectric devices. The green light emitting diode comprises a substrate, and a buffer layer, an intrinsic GaN layer, an N-type GaN layer, an active layer, an electron barrier layer and a P-type GaN layer which are sequentially arranged on the substrate, wherein the active layer comprises a plurality of quantum well layers and quantum barrier layers which are alternately stacked; each quantum well layer comprises a plurality of InN nanorods and an InGaN cladding layer wrapped on the InN nanorods. The invention can improve the luminous efficiency and wavelength uniformity of the green light emitting diode.
Description
Technical Field
The invention relates to the field of semiconductor photoelectric devices, in particular to a green light emitting diode epitaxial wafer, a preparation method thereof and a green light emitting diode.
Background
At present, gaN-based light emitting diodes have been widely applied to the solid state lighting field and the display field, and attract more and more people to pay attention. GaN-based leds have been produced industrially and are used in backlights, illuminations, landscape lamps, etc.
The epitaxial wafer is a main component of the light emitting diode, and the conventional GaN-based light emitting diode epitaxial wafer comprises a substrate, and a buffer layer, an intrinsic GaN layer, an N-type semiconductor layer, a multi-quantum well layer, an electron blocking layer and a P-type semiconductor layer which are sequentially laminated on the substrate.
Among them, the green light emitting diode generally requires the growth of a high indium composition multiple quantum well layer. The traditional multi-quantum well layer is a composite structure formed by repeatedly and periodically laminating InGaN quantum well layers and GaN quantum barrier layers; however, because of the larger lattice mismatch between the InGaN quantum well layer and the GaN quantum barrier layer, the InGaN material with high indium content generally has the disadvantages of poor crystal quality and high non-radiative recombination rate. In addition, a strong built-in electric field can be generated by large stress between GaN and InGaN, so that quantum confinement Stark effect is caused, and therefore, electron and hole wave function space separation is caused, and effective radiation recombination rate is greatly reduced; and because the In component is high, serious In clustering phenomenon exists, so that the In distribution is extremely uneven, and the wavelength uniformity In the multiple quantum well is poor.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a green light emitting diode epitaxial wafer and a preparation method thereof, which can improve the light efficiency and wavelength uniformity of a green light emitting diode.
The technical problem to be solved by the present invention is to provide a green light emitting diode with high light efficiency and good wavelength uniformity.
In order to solve the problems, the invention discloses a green light emitting diode epitaxial wafer which comprises a substrate, and a buffer layer, an intrinsic GaN layer, an N-type GaN layer, an active layer, an electronic barrier layer and a P-type GaN layer which are sequentially arranged on the substrate, wherein the active layer comprises a plurality of quantum well layers and quantum barrier layers which are alternately stacked; each quantum well layer comprises a plurality of InN nanorods and an InGaN cladding layer wrapped on the InN nanorods.
As an improvement of the technical scheme, the content of the In component In each InN nanorod is 0.4-0.6, and the content of the In component In the InGaN cladding layer is 0.2-0.4.
As an improvement of the technical scheme, an InAlGaN cladding layer is further arranged on the InGaN cladding layer, the content of an In component In the InAlGaN cladding layer is 0.05-0.2, and the content of an Al component In the InAlGaN cladding layer is 0.01-0.05;
the content of the In component In each InN nanorod is 0.45-0.65, and the content of the In component In the InGaN cladding layer is 0.25-0.4.
As an improvement of the technical scheme, the diameter of the InN nano-rods is 5-100 nm, the length of the InN nano-rods is 5-20 nm, and the distance between adjacent InN nano-rods is 5-50 nm;
the thickness of the InGaN coating layer is 1nm-3nm, and the thickness of the InAlGaN coating layer is 1nm-3nm.
As an improvement of the technical scheme, the quantum barrier layer is of a periodic structure, each period comprises an N-GaN layer and an AlGaN layer which are sequentially stacked, and the period number of the quantum barrier layer is more than or equal to 2.
As an improvement of the technical scheme, the number of cycles of the quantum barrier layer is 3-6, the thickness of the single N-GaN layer is 1nm-3nm, and the doping concentration is 1 multiplied by 10 15 cm -3 -1×10 16 cm -3 The thickness of the single AlGaN layer is 1nm-3nm, and the content of the Al component is 0.1-0.5.
Correspondingly, the invention also discloses a preparation method of the green light emitting diode epitaxial wafer, which is used for preparing the green light emitting diode and comprises the following steps:
providing a substrate, and growing a buffer layer, an intrinsic GaN layer, an N-type GaN layer, an active layer, an electron barrier layer and a P-type GaN layer on the substrate in sequence, wherein the active layer comprises a plurality of quantum well layers and quantum barrier layers which are alternately stacked; each quantum well layer comprises a plurality of InN nanorods and an InGaN coating layer wrapped on the InN nanorods;
the preparation method of the InN nanorod comprises the following steps: and growing an InN layer, and etching to form a plurality of InN nanorods.
As an improvement of the technical scheme, the growth temperature of the InN layer is 700-750 ℃, the growth pressure is 100-500torr, and the carrier gas adopted during growth is nitrogen or argon;
the growth temperature of the InGaN coating layer is 750-770 ℃, the growth pressure is 100-500torr, and the carrier gas used during growth is nitrogen or argon.
As an improvement of the above technical solution, the quantum well layer further comprises an InAlGaN cladding layer disposed on the InGaN cladding layer, the growth temperature of the InAlGaN cladding layer is 770 ℃ to 800 ℃, the growth pressure is 100torr to 500torr, and the carrier gas used during growth is nitrogen or argon;
the quantum barrier layer is of a periodic structure, and each period comprises an N-GaN layer and an AlGaN layer which are sequentially stacked; the growth temperature of the N-GaN layer is 850-900 ℃, and the growth pressure is 100-500 torr;
the growth temperature of the AlGaN layer is 850-900 ℃, and the growth pressure is 100-500torr.
Correspondingly, the invention also discloses a green light emitting diode which comprises the green light emitting diode epitaxial wafer.
The implementation of the invention has the following beneficial effects:
1. in the green light emitting diode epitaxial wafer, the quantum well layer adopts a core-shell structure, namely an InN nanorod is used as a core, and an InGaN coating layer is used as a shell. The InN nano rod can respectively release stress in three dimensions, so that dislocation and defects are avoided, and the defect density in the active layer is reduced. Meanwhile, the compressive strain in the quantum well is relaxed in an elastic deformation mode, so that the compressive strain and the piezoelectric field in the quantum well are remarkably reduced, the quantum confinement Stark effect is inhibited, and the luminous efficiency is improved. Moreover, in atoms and Ga atoms tend to migrate, diffuse and be fused into the InN nanorods through lateral surfaces, and because the diffusion potential barrier is lower, the uniform distribution of In is more facilitated, and the defects are fewer, and under the condition of stress reduction, the segregation of the In atoms can also be reduced, the content of an In component can be greatly improved under the condition of not adopting a low temperature, the uniformity of the In component is also improved, and the luminous efficiency and the luminous wavelength uniformity of green light are improved. Furthermore, although the InN nanorod has the advantages, the stability of the InN material is poor, so that an InGaN cladding layer is introduced to improve the stability of the quantum well layer.
2.In the green light emitting diode epitaxial wafer, the InAlGaN coating layer is further arranged on the coating layer of the InGaN layer, the Al component is introduced into the InAlGaN coating layer, and the integrity of a GaN crystal lattice can be maintained because the strength of a covalent bond between an Al atom and an N atom is far greater than that of a covalent bond between a Ga atom and an N atom, so that the crystal lattice quality of a crystal formed by a quantum well layer is further improved, and the content of an In component In the quantum well layer is further improved.
3. In the green light emitting diode epitaxial wafer, the quantum barrier layer is a periodically stacked N-GaN layer and an AlGaN layer. And the growth of the quantum well layer is a two-dimensional merging process, and the core-shell structure of the quantum well layer can be gradually filled. And the N-GaN layer can increase the concentration and the concentration expansion capability of electrons in the multiple quantum wells, and the Al introduced into the AlGaN layer can improve the lattice quality of the quantum barrier layer, thereby being beneficial to filling and leveling of the core-shell structure.
The quantum barrier layer is a two-dimensional merging process and gradually fills and levels the core-shell structure. The quantum barrier layer is a periodic structure formed by repeatedly laminating an N-type doped GaN layer and an AlGaN layer, the intermittent N-type doping is used for increasing the electron concentration and the electron expansion capacity in a multi-quantum well, and the intermittent Al doping is used for forming a good-quality crystal lattice because Al atoms are small and covalent bonds between the Al atoms and the N atoms are strong.
Drawings
FIG. 1 is a schematic structural diagram of a green light emitting diode epitaxial wafer according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of an active layer according to an embodiment of the present invention;
FIG. 3 is a schematic diagram illustrating the distribution positions of InN nanorods according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of the distribution positions of InN nanorods in another embodiment of the present invention;
FIG. 5 is a schematic structural diagram of an active layer according to another embodiment of the present invention;
FIG. 6 is a schematic structural diagram of a quantum barrier layer in an embodiment of the invention;
fig. 7 is a flowchart of a method for manufacturing an epitaxial wafer for a green led according to an embodiment of the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below.
Referring to fig. 1 and 2, the invention discloses a green light emitting diode epitaxial wafer, which comprises a substrate 1, and a buffer layer 2, an intrinsic GaN layer 3, an N-type GaN layer 4, an active layer 5, an electron blocking layer 6 and a P-type GaN layer 7 which are sequentially arranged on the substrate 1. The active layer 5 includes a plurality of quantum well layers 51 and quantum barrier layers 52 stacked alternately, and the number of stacking cycles is 2 to 10.
Wherein each quantum well layer 51 comprises a plurality of InN nanorods 511 and an InGaN cladding layer 512 wrapped around the InN nanorods 511. Based on the structure, the In component In the quantum well layer 51 can be improved, the lattice quality of the In component can be improved, the In component In the quantum well layer 51 is uniformly distributed, and the piezoelectric field is obviously reduced, so that the quantum confinement Stark effect is inhibited, the wave functions of electrons and holes are overlapped and increased, and the green light emitting diode with high luminous efficiency and good wavelength uniformity is obtained.
The cross section of the InN nanorod 511 is circular, triangular, quadrilateral, trapezoidal or polygonal (the number of sides is greater than or equal to 5), that is, the InN nanorod 511 is cylindrical, prismatic (triangular prism, quadrangular prism or polygonal prism) or prismoid as a whole, but not limited thereto. The InN nanorods 511 with various shapes can release stress in three dimensions, avoid dislocation and defect generation, and reduce defect density in the active layer. Specifically, the height of the InN nano rod 511 is 3nm-15nm, and the length is 5nm-20nm. It should be noted that the height here refers to a linear distance from the bottom of the InN nanorod 511 to the highest point, and if the InN nanorod 511 is circular, the height is a diameter; when the InN nanorods are triangular/trapezoidal, they are triangular (trapezoidal) high, but not limited thereto. Preferably, the cross section of the InN nanorod 511 is circular, that is, the InN nanorod 511 is cylindrical as a whole, and based on the structure, the diffusion and the incorporation of In on the surface of the nanorod can be effectively promoted, so that the content of an In component can be further improved, and the uniform distribution of the In component is also facilitated. Specifically, in the embodiment, the diameter of the InN nanorod is 5nm to 100nm, and when the diameter is less than 5nm, the In fusion effect is poor, and the In component content improvement effect is poor; when the diameter is larger than 100nm, the difference caused by the core-shell structure is large, so that the core-shell structure is difficult to fill and level effectively, and the luminous efficiency is influenced. Illustratively, the InN nanorods 511 have a diameter of 6nm, 15nm, 24nm, 33nm, 42nm, 51nm, 60nm, 69nm, 78nm, 87nm, or 96nm, but are not limited thereto. The length of the InN nanorod 511 is 5nm-20nm, and exemplary is 5nm, 8nm, 11nm, 14nm or 17nm, but is not limited thereto.
Specifically, the InN nanorods 511 are distributed in the quantum well layer 51 in an array, for example, in an embodiment of the present invention, referring to fig. 3, a plurality of InN nanorods 511 are distributed in multiple rows in the quantum well layer 51, and in each row of InN nanorods 511, the spacing between adjacent InN nanorods 511 is the same, and is 5nm-50nm; the InN nanorods 511 of adjacent rows are aligned in one direction (Y direction in FIG. 3), and a spacing of 5nm to 50nm (i.e., in the Y direction) is also provided between the InN nanorods 511 of adjacent rows. In another embodiment of the invention, referring to fig. 4, the InN nanorods 511 are not disposed within a distance of 8 to 12% of the edge of each epitaxial wafer, a plurality of InN nanorods 511 are distributed in multiple rows, and the distances between adjacent InN nanorods 511 in each row are the same and are all 5nm to 50nm. The InN nanorods between adjacent rows are distributed in a staggered manner, and the spacing between the InN nanorods in the Y direction is 0. Based on the structure, the filling of the core-shell structure of the quantum well layer 51 in the later period is facilitated. It should be noted that the distribution form of the array of the InN nanorods 511 In the present invention is not limited to the above embodiment, and those skilled In the art can adjust the distribution form of the InN nanorods 511 according to the content requirement of the In component In the quantum well layer and the filling requirement.
Specifically, the In component content of the InN nanorods 511 is 0.4-0.6, and illustratively 0.43, 0.46, 0.49, 0.52, 0.55, or 0.58, but is not limited thereto.
The In component content of the InGaN cladding layer 512 is 0.2-0.4, and the In component is lower than that of the InN nano rod 511, so that the overall stability of the quantum well layer 51 can be improved. Illustratively, the In component content of the InGaN cladding layer 512 is 0.22, 0.24, 0.26, 0.28, 0.3, 0.32, 0.34, 0.36, or 0.38, but is not limited thereto. Specifically, the InGaN cladding layer 512 has a thickness of 1nm to 3nm, and illustratively 1.3nm, 1.6nm, 1.9nm, 2.2nm, 2.5nm, or 2.8nm, but is not limited thereto.
Preferably, in an embodiment of the present invention, referring to fig. 5, an InAlGaN cladding layer 513 is further disposed on the InGaN cladding layer 512, and an Al component is introduced into the InAlGaN cladding layer, so as to further improve the lattice quality of the crystal formed by the quantum well layer 51, and further improve the In component content In the quantum well layer 51. Specifically, after the layer is introduced, the In component In a single InN nanorod 511 can be increased to 0.45-0.65, and the In component In an InGaN coating layer 512 can be increased to 0.25-0.4.
Specifically, the content of the In component In the InAlGaN cladding layer 513 is 0.05 to 0.2, and illustratively 0.07, 0.1, 0.13, 0.15, or 0.18, but is not limited thereto. The content of the Al component in the InAlGaN cladding layer 513 is 0.01 to 0.05, and illustratively 0.02, 0.025, 0.03, 0.04, or 0.045, but is not limited thereto. The thickness of the InAlGaN cladding layer 513 is 1nm to 3nm, and is illustratively 1.4nm, 1.8nm, 2.2nm, 2.6nm, or 2.9nm, but is not limited thereto.
The quantum barrier layer 52 may be a GaN barrier layer commonly used in the art, but is not limited thereto. Preferably, referring to fig. 6, in an embodiment of the present invention, the quantum barrier layer 52 has a periodic structure, each period includes an N-GaN layer 521 and an AlGaN layer 522 stacked in sequence, and a core-shell structure filling the quantum well layer 51 can be ensured by the quantum barrier layer 52 having such a structure; the two can increase the concentration and concentration expansion capability of electrons in the multiple quantum well and improve the luminous efficiency.
Specifically, the number of cycles of quantum barrier layer 52 is 3-6.The thickness of the N-GaN layer 521 is 1nm to 3nm, and is illustratively 1.3nm, 1.6nm, 1.9nm, 2.2nm, 2.5nm, or 2.9nm, but is not limited thereto. The doping element of the N-GaN layer 521 is Si, but is not limited thereto. The doping concentration is 1 x 10 15 cm -3 -1×10 16 cm -3 Exemplary is 2.5 × 10 15 cm -3 、4×10 15 cm -3 、5.5×10 15 cm -3 、7×10 15 cm -3 Or 8.5X 10 15 cm -3 。
Specifically, the AlGaN layer 522 has a thickness of 1nm to 3nm, and is illustratively 1.25nm, 1.5nm, 1.75nm, 2nm, 2.25nm, 2.5nm, or 2.75nm, but is not limited thereto. The Al component is contained in an amount of 0.1 to 0.5, and exemplary is 0.22, 0.27, 0.35, 0.37, 0.42 or 0.46, but not limited thereto.
The substrate 1 may be, but not limited to, a sapphire substrate, a silicon substrate, or a silicon carbide substrate.
The buffer layer 2 may be, but not limited to, an AlN layer and/or an AlGaN layer; preferably, the buffer layer 2 is an AlN layer. The thickness of the buffer layer 2 is 20nm to 100nm, and is illustratively 25nm, 35nm, 45nm, 55nm, 65nm, 75nm, or 90nm, but is not limited thereto.
The thickness of the intrinsic GaN layer 3 is 300nm to 800nm, and is exemplified by 350nm, 400nm, 450nm, 500nm, 550nm, 600nm, 650nm, or 750nm, but is not limited thereto.
The doping element of the N-type GaN layer 4 is Si, but not limited thereto. The doping concentration of the N-type GaN layer 4 is 5X 10 18 cm -3 -1×10 19 cm -3 The thickness is 1 μm to 3 μm, and 1.2 μm, 1.5 μm, 1.7 μm, 2.1 μm, 2.4 μm, 2.6 μm, or 2.9 μm are exemplary, but not limited thereto.
The electron blocking layer 6 is an AlGaN layer or an AlInGaN layer, but is not limited thereto. Preferably, in one embodiment of the present invention, the electron blocking layer 6 is Al a Ga 1-a N layer and In b Ga 1-b N layers of periodic structures are alternately grown; wherein a is 0.05-0.2, and b is 0.1-0.5. The thickness of the electron blocking layer 6 is 20nm to 150nm, and exemplary is 50nm, 80nm, 110nm, 125nm, or 140nm, but is not limited thereto.
The doping element in the P-type GaN layer 7 is Mg, but not limited thereto. The doping concentration of Mg in the P-type GaN layer 7 is 5X 10 17 cm -3 -1×10 20 cm -3 . The thickness of the P-type GaN layer 7 is 20nm-130nm.
Correspondingly, referring to fig. 7, the present application also discloses a method for preparing a green light emitting diode epitaxial wafer, which is used for preparing the green light emitting diode epitaxial wafer, and comprises the following steps:
s100: providing a substrate;
preferably, in one embodiment of the present invention, the substrate is loaded into MOCVD, and annealed at 1000 ℃ -1200 ℃ under 200torr-600torr in hydrogen atmosphere for 5min-8min, so as to remove particles, oxides and other impurities on the surface of the substrate.
S200: sequentially growing a buffer layer, an intrinsic GaN layer, an N-GaN layer, an active layer, an electron blocking layer and a P-type GaN layer on a substrate;
specifically, S200 includes:
s210: growing a buffer layer on a substrate;
specifically, an AlGaN layer may be grown by MOCVD as a buffer layer, or an AlN layer may be grown by PVD as a buffer layer, but is not limited thereto. Preferably, the AlN layer is grown using PVD.
S220: growing an intrinsic GaN layer on the buffer layer;
specifically, an intrinsic GaN layer is grown in MOCVD at 1100-1150 deg.C under 100-500torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As a source of N; with H 2 And N 2 As carrier gas, TMGa was introduced as Ga source.
S230: growing an N-GaN layer on the intrinsic GaN layer;
specifically, an N-GaN layer grows in MOCVD at the growth temperature of 1100-1150 ℃ and the growth pressure of 100-500torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As a source of N, siH is introduced 4 As N-type doping source; with H 2 And N 2 As carrier gas, TMGa was fed as Ga source.
S240: growing an active layer on the N-GaN layer;
specifically, a quantum well layer and a quantum barrier layer are periodically grown in MOCVD to form an active layer.
Specifically, in one embodiment of the present invention, growing the quantum well layer includes:
s11: growing an InN layer;
specifically, the InN layer may be formed by PECVD, MOCVD, EBL, etc., but is not limited thereto. Preferably, in one embodiment of the present invention, the InN layer is grown in MOCVD at a growth temperature of 700 ℃ to 750 ℃ and a growth pressure of 100torr to 500torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As N source, with Ar or N 2 As a carrier gas, TMIn was introduced as an In source.
It should be noted that, since the present invention employs the quantum well layer with a specific structure, the present invention does not need to employ the conventional low-temperature growth method (to obtain the quantum well layer with a high In composition). Therefore, the growth temperature of the invention is higher, and is 700-750 ℃, and the high-temperature growth is beneficial to improving the crystal lattice quality and improving the distribution uniformity of In components.
S12: etching the InN layer to form a plurality of InN nanorods;
specifically, the etching may be performed by dry etching (such as ICP, but not limited thereto) or wet etching (such as AZ400K wet etching solution, but not limited thereto). Preferably, an ICP etching system is adopted to etch the InN layer to form the InN nano rod.
S13: growing an InGaN coating layer on the InN nano rod;
specifically, an InGaN cladding layer is grown in MOCVD, the growth temperature is 750-770 ℃, and the growth pressure is 100-500torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As N source, with N 2 Or Ar is used as a carrier gas, TMIn is introduced to be used as an In source, and TEGa is introduced to be used as a Ga source.
Preferably, in an embodiment of the present invention, the step of growing the quantum well layer further includes:
s14: growing an InAlGaN cladding layer on the InGaN cladding layer;
specifically, inAlGaN cladding layer is grown in MOCVD at 770-800 deg.C and 100torr500torr, NH is introduced into the MOCVD reaction chamber during growth 3 As N source, with N 2 Or Ar is used as a carrier gas, TMAl is introduced as an Al source, TMIn is introduced as an In source, and TEGa is introduced as a Ga source.
Specifically, in one embodiment of the invention, a GaN barrier layer is grown as a quantum barrier layer, the growth temperature is 800-900 ℃, the growth pressure is 100-500torr, and NH is introduced into an MOCVD reaction chamber during growth 3 As N source, with H 2 And N 2 As carrier gas, TEGa was introduced as Ga source.
Preferably, in an embodiment of the present invention, the growing the quantum barrier layer comprises the following steps:
s21: growing an N-GaN layer;
specifically, an N-GaN layer grows in MOCVD at the growth temperature of 850-900 ℃ and the growth pressure of 100-500 torr; during growth, NH is introduced into the MOCVD reaction chamber 3 As a source of N, siH is introduced 4 As N-type doping source; with H 2 And N 2 As carrier gas, TMGa was fed as Ga source.
S22: growing an AlGaN layer on the N-GaN layer;
specifically, an AlGaN layer grows in MOCVD at the growth temperature of 850-900 ℃ and the growth pressure of 100-500 torr; during growth, NH is introduced into the MOCVD reaction chamber 3 As N source, with H 2 And N 2 As a carrier gas, TMAl was introduced as an Al source, and TMGa was introduced as a Ga source.
S23: and repeating the steps S21 and S22 periodically until the quantum barrier layer is obtained.
S250: growing an electron blocking layer on the active layer;
specifically, al is periodically grown in MOCVD a Ga 1-a N layer and In b Ga 1-b And the N layer is used as an electron blocking layer. Wherein, al a Ga 1-a The growth temperature of the N layer is 900-1000 ℃, and the growth pressure is 100-500torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As N source, with N 2 And H 2 As carrier gas, TMAl is introduced as Al source, and TMGa is introduced as Ga source. In (In) b Ga 1-b Growth temperature of N layer900-1000 deg.c and growth pressure of 100-500torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As N source, with N 2 And H 2 As a carrier gas, TMIn is introduced as an In source, and TMGa is introduced as a Ga source.
S260: growing a P-type GaN layer on the electron blocking layer;
specifically, a P-type GaN layer grows in MOCVD at the growth temperature of 800-1000 ℃ and the growth pressure of 100-300 torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As N source, cp is introduced 2 Mg is used as a P-type doping source; with H 2 And N 2 As carrier gas, TMGa was fed as Ga source.
The invention is further illustrated by the following specific examples:
example 1
The present embodiment provides a green light emitting diode epitaxial wafer, referring to fig. 1, fig. 2, and fig. 4, which includes a substrate 1, and a buffer layer 2, an intrinsic GaN layer 3, an N-type GaN layer 4, an active layer 5, an electron blocking layer 6, and a P-type GaN layer 7 sequentially disposed on the substrate 1.
Wherein, the substrate 1 is a sapphire substrate, the buffer layer 2 is an AlN layer, and the thickness of the AlN layer is 30nm; the thickness of the intrinsic GaN layer 3 was 500nm. The doping concentration of Si in the N-type GaN layer 4 was 9X 10 18 cm -3 The thickness thereof was 2 μm.
The active layer 5 includes quantum well layers 51 and quantum barrier layers 52 (GaN layers, each having a thickness of 4 nm) alternately stacked, and the number of stacking cycles is 7. Each quantum well layer 51 includes a plurality of arrays of InN nanorods 511 and an InGaN cladding layer 512 wrapped around the InN nanorods 511. The InN nanorod 511 is circular in cross section, 15nm in diameter and 80nm in length. The plurality of InN nanorods 511 are distributed in multiple rows, and the distances between adjacent InN nanorods 511 in each row are the same and are all 15nm. The InN nanorods between adjacent rows are distributed in a staggered manner, and the distance between the InN nanorods in the Y direction is 0. The In component content of each InN nanorod is 0.42. The In component content of the InGaN clad layer 512 was 0.22, and the thickness was 2nm.
Wherein the electron blocking layer 6 is Al a Ga 1-a N layer (a = 0.14) and In b Ga 1-b Week of alternate growth of N layers (b = 0.4)Periodic structure with 8 cycles of single Al a Ga 1-a The thickness of the N layer was 6nm, single In b Ga 1-b The thickness of the N layer was 6nm. The doping element of the P-type GaN layer 7 is Mg, and the doping concentration is 5 multiplied by 10 18 cm -3 The thickness was 40nm.
The preparation method of the green light emitting diode epitaxial wafer in the embodiment comprises the following steps:
(1) Providing a substrate; the substrate was loaded into MOCVD and annealed at 1150 ℃ at 450torr in a hydrogen atmosphere for 6min.
(2) Growing a buffer layer on a substrate;
specifically, an AlN layer is grown using PVD.
(3) Growing an intrinsic GaN layer on the buffer layer;
specifically, an intrinsic GaN layer is grown by MOCVD (metal organic chemical vapor deposition), the growth temperature is 1120 ℃, the growth pressure is 300torr, and NH is introduced into an MOCVD reaction chamber during growth 3 As a source of N; with H 2 And N 2 As carrier gas, TMGa was fed as Ga source.
(4) Growing an N-GaN layer on the intrinsic GaN layer;
specifically, an N-GaN layer is grown by MOCVD, the growth temperature is 1120 ℃, and the growth pressure is 200torr; during growth, NH is introduced into the MOCVD reaction chamber 3 As a source of N, siH is introduced 4 As N-type doping source; with H 2 And N 2 As carrier gas, TMGa was fed as Ga source.
(5) Growing an active layer on the N-GaN layer;
specifically, a quantum well layer and a quantum barrier layer are periodically grown in MOCVD to obtain an active layer;
wherein the growth temperature of the quantum barrier layer is 820 ℃, the growth pressure is 300torr, and NH is introduced into the MOCVD reaction chamber during growth 3 As N source, with H 2 And N 2 As carrier gas, TEGa was introduced as Ga source.
The preparation method of each quantum well layer comprises the following steps:
growing an InN layer;
specifically, the InN layer is grown by MOCVD. The growth temperature was 740 ℃ and the growth pressure was 200torr. Raw materialIntroducing NH into the MOCVD reaction chamber for a long time 3 As N source, with N 2 As a carrier gas, TMIn was introduced as an In source.
(II) etching the InN layer to form a plurality of InN nanorods;
and etching the InN layer by adopting an ICP etching system to form the InN nano rod.
(III) growing an InGaN coating layer on the InN nanorod;
specifically, an InGaN cladding layer is grown in MOCVD, the growth temperature is 760 ℃, and the growth pressure is 200torr. When growing InGaN cladding layer, NH is introduced into an MOCVD reaction chamber 3 As a source of N; with N 2 As a carrier gas, TMIn was introduced as an In source, and TEGa was introduced as a Ga source.
(6) Growing an electron blocking layer on the active layer;
specifically, MOCVD is adopted to periodically grow Al a Ga 1-a N layer and In b Ga 1-b N layer as electron blocking layer, wherein Al a Ga 1-a The growth temperature of the N layer is 950 ℃ and the growth pressure is 300torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As N source, with N 2 And H 2 As a carrier gas, TMAl was introduced as an Al source, and TMGa was introduced as a Ga source. In b Ga 1-b The growth temperature of the N layer is 950 ℃, and the growth pressure is 300torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As N source, with N 2 And H 2 As a carrier gas, TMIn is introduced as an In source, and TMGa is introduced as a Ga source.
(7) Growing a P-type GaN layer on the electron barrier layer;
specifically, a P-GaN layer is grown by MOCVD, the growth temperature is 850 ℃, and the growth pressure is 200torr; during growth, NH is introduced into the MOCVD reaction chamber 3 As N source, cp is introduced 2 Mg is used as a P-type doping source; with H 2 And N 2 As carrier gas, TMGa was fed as Ga source.
Example 2
The embodiment provides a green light emitting diode epitaxial wafer, which comprises a substrate 1, and a buffer layer 2, an intrinsic GaN layer 3, an N-type GaN layer 4, an active layer 5, an electron blocking layer 6 and a P-type GaN layer 7 which are sequentially arranged on the substrate 1, as shown in fig. 1, 4 and 5.
Wherein, the substrate 1 is a sapphire substrate, the buffer layer 2 is an AlN layer, and the thickness of the AlN layer is 30nm; the thickness of the intrinsic GaN layer 3 was 500nm. The doping concentration of Si in the N-type GaN layer 4 was 9X 10 18 cm -3 The thickness was 2 μm.
The active layer 5 includes quantum well layers 51 and quantum barrier layers 52 (GaN layers, each having a thickness of 4 nm) stacked alternately, and the number of stacking periods is 7. Each quantum well layer 51 comprises a plurality of arrays of InN nanorods 511, an InGaN cladding layer 512 wrapped around the InN nanorods 511, and an InAlGaN cladding layer laminated on the InGaN cladding layer 512. The InN nanorod 511 is circular in cross section, 15nm in diameter and 80nm in length. The plurality of InN nanorods 511 are distributed in multiple rows, and the distances between adjacent InN nanorods 511 in each row are the same and are all 15nm. The InN nanorods between adjacent rows are distributed in a staggered manner, and the spacing between the InN nanorods in the Y direction is 0. The In component content of each InN nano rod is 0.5. The In component content of the InGaN clad layer 512 was 0.28, and the thickness was 2nm. The InAlGaN cladding layer 513 contains 0.15 of In component, 0.32 of Al component and 1nm of thickness.
Wherein the electron blocking layer 6 is Al a Ga 1-a N layer (a = 0.14) and In b Ga 1-b Periodic structure with N layers (b = 0.4) grown alternately with a period number of 8, single Al a Ga 1-a The thickness of the N layer was 6nm, single In b Ga 1-b The thickness of the N layer was 6nm. The doping element of the P-type GaN layer 7 is Mg, and the doping concentration is 5 multiplied by 10 18 cm -3 And the thickness is 40nm.
The preparation method of the green light emitting diode epitaxial wafer in the embodiment comprises the following steps:
(1) Providing a substrate; the substrate was loaded into MOCVD and annealed at 1150 ℃ at 450torr in a hydrogen atmosphere for 6min.
(2) Growing a buffer layer on a substrate;
specifically, an AlN layer was grown using PVD.
(3) Growing an intrinsic GaN layer on the buffer layer;
specifically, an intrinsic GaN layer is grown by MOCVD at a growth temperature of 1At 120 ℃, the growth pressure is 300torr, NH is introduced into the MOCVD reaction chamber during growth 3 As a source of N; with H 2 And N 2 As carrier gas, TMGa was fed as Ga source.
(4) Growing an N-GaN layer on the intrinsic GaN layer;
specifically, an N-GaN layer is grown by MOCVD, the growth temperature is 1120 ℃, and the growth pressure is 200torr; during growth, NH is introduced into the MOCVD reaction chamber 3 As a source of N, siH is introduced 4 As N-type doping source; with H 2 And N 2 As carrier gas, TMGa was fed as Ga source.
(5) Growing an active layer on the N-GaN layer;
specifically, a quantum well layer and a quantum barrier layer are periodically grown in MOCVD to obtain an active layer;
wherein the growth temperature of the quantum barrier layer is 820 ℃, the growth pressure is 300torr, and NH is introduced into the MOCVD reaction chamber during growth 3 As N source, with H 2 And N 2 As carrier gas, TEGa was introduced as Ga source.
The preparation method of each quantum well layer comprises the following steps:
growing an InN layer;
specifically, an InN layer is grown by MOCVD. The growth temperature was 740 ℃ and the growth pressure was 200torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As N source, with N 2 As a carrier gas, TMIn was introduced as an In source.
(II) etching the InN layer to form a plurality of InN nanorods;
and etching the InN layer by adopting an ICP etching system to form the InN nano rod.
(III) growing an InGaN coating layer on the InN nanorod;
specifically, an InGaN cladding layer is grown in MOCVD, the growth temperature is 760 ℃, and the growth pressure is 200torr. When growing InGaN cladding layer, NH is introduced into an MOCVD reaction chamber 3 As a source of N; with N 2 As a carrier gas, TMIn was introduced as an In source, and TEGa was introduced as a Ga source.
(IV) growing an InAlGaN cladding layer on the InGaN cladding layer;
specifically, inAnd growing an InAlGaN coating layer in MOCVD at the growth temperature of 790 ℃ and the growth pressure of 200torr. When growing InAlGaN coating layer, NH is introduced into MOCVD reaction chamber 3 As a source of N; with N 2 As a carrier gas, TMAl is introduced as an Al source, TMIn is introduced as an In source, and TEGa is introduced as a Ga source.
(6) Growing an electron blocking layer on the active layer;
specifically, MOCVD is adopted to periodically grow Al a Ga 1-a N layer and In b Ga 1-b N layer as electron blocking layer, wherein Al a Ga 1-a The growth temperature of the N layer is 950 ℃, and the growth pressure is 300torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As N source, with N 2 And H 2 As a carrier gas, TMAl was introduced as an Al source, and TMGa was introduced as a Ga source. In b Ga 1-b The growth temperature of the N layer is 950 ℃ and the growth pressure is 300torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As N source, with N 2 And H 2 As a carrier gas, TMIn is introduced as an In source, and TMGa is introduced as a Ga source.
(7) Growing a P-type GaN layer on the electron blocking layer;
specifically, an MOCVD is adopted to grow a P-GaN layer, the growth temperature is 850 ℃, and the growth pressure is 200torr; during growth, NH is introduced into the MOCVD reaction chamber 3 As N source, cp is introduced 2 Mg is used as a P-type doping source; with H 2 And N 2 As carrier gas, TMGa was fed as Ga source.
Example 3
The present embodiment provides an epitaxial wafer for a green light emitting diode, which is shown in fig. 1, 4, 5 and 6 and comprises a substrate 1, and a buffer layer 2, an intrinsic GaN layer 3, an N-type GaN layer 4, an active layer 5, an electron blocking layer 6 and a P-type GaN layer 7 which are sequentially disposed on the substrate 1.
Wherein, the substrate 1 is a sapphire substrate, the buffer layer 2 is an AlN layer, and the thickness of the AlN layer is 30nm; the thickness of the intrinsic GaN layer 3 was 500nm. The doping concentration of Si in the N-type GaN layer 4 was 9X 10 18 cm -3 The thickness was 2 μm.
The active layer 5 includes quantum well layers 51 and quantum barrier layers 52 alternately stacked, and the number of stacking cycles is 7. Each quantum well layer 51 comprises a plurality of arrays of InN nanorods 511, an InGaN cladding layer 512 wrapped around the InN nanorods 511, and an InAlGaN cladding layer laminated on the InGaN cladding layer 512. The InN nanorod 511 is circular in cross section, 15nm in diameter and 80nm in length. The plurality of InN nanorods 511 are distributed in multiple rows, and the distances between adjacent InN nanorods 511 in each row are the same and are all 15nm. The InN nanorods between adjacent rows are distributed in a staggered manner, and the spacing between the InN nanorods in the Y direction is 0. The In component content of each InN nano rod is 0.5. The In component content of the InGaN clad layer 512 was 0.28, and the thickness was 2nm. The InAlGaN cladding layer 513 contains 0.15 of In component, 0.32 of Al component and 1nm of thickness.
Specifically, each quantum barrier layer 52 has a periodic structure, and the period number is 4. Each period includes an N-GaN layer 521 and an AlGaN layer 522 which are sequentially stacked. Wherein the doping element of the N-GaN layer 521 is Si, and the doping concentration is 1.5 × 10 15 cm -3 The thickness is 2nm; the AlGaN layer 522 had an Al component content of 0.25 and a thickness of 2nm.
Wherein the electron blocking layer 6 is Al a Ga 1-a N layer (a = 0.14) and In b Ga 1-b Periodic structure with N layers (b = 0.4) grown alternately with a period number of 8, single Al a Ga 1-a The thickness of the N layer was 6nm, single In b Ga 1-b The thickness of the N layer was 6nm. The doping element of the P-type GaN layer 7 is Mg, and the doping concentration is 5 multiplied by 10 18 cm -3 And the thickness is 40nm.
The preparation method of the green light emitting diode epitaxial wafer in the embodiment comprises the following steps:
(1) Providing a substrate; the substrate was loaded into MOCVD and annealed at 1150 ℃ for 6min at 450torr in a hydrogen atmosphere.
(2) Growing a buffer layer on a substrate;
specifically, an AlN layer is grown using PVD.
(3) Growing an intrinsic GaN layer on the buffer layer;
specifically, an intrinsic GaN layer is grown by MOCVD (metal organic chemical vapor deposition), the growth temperature is 1120 ℃, the growth pressure is 300torr, and NH is introduced into an MOCVD reaction chamber during growth 3 As a source of N; to be provided withH 2 And N 2 As carrier gas, TMGa was introduced as Ga source.
(4) Growing an N-GaN layer on the intrinsic GaN layer;
specifically, an N-GaN layer is grown by MOCVD, the growth temperature is 1120 ℃, and the growth pressure is 200torr; during growth, NH is introduced into the MOCVD reaction chamber 3 As a source of N, siH is introduced 4 As N-type doping source; with H 2 And N 2 As carrier gas, TMGa was fed as Ga source.
(5) Growing an active layer on the N-GaN layer;
specifically, a quantum well layer and a quantum barrier layer are periodically grown in MOCVD to obtain an active layer;
the preparation method of each quantum well layer comprises the following steps:
growing an InN layer;
specifically, an InN layer is grown by MOCVD. The growth temperature was 740 ℃ and the growth pressure was 200torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As N source, with N 2 As a carrier gas, TMIn was introduced as an In source.
(II) etching the InN layer to form a plurality of InN nanorods;
and etching the InN layer by adopting an ICP etching system to form the InN nano rod.
(III) growing an InGaN coating layer on the InN nanorod;
specifically, an InGaN cladding layer is grown in MOCVD, the growth temperature is 760 ℃, and the growth pressure is 200torr. When growing InGaN cladding layer, NH is introduced into an MOCVD reaction chamber 3 As a source of N; with N 2 As a carrier gas, TMIn was introduced as an In source, and TEGa was introduced as a Ga source.
(IV) growing an InAlGaN cladding layer on the InGaN cladding layer;
specifically, an InAlGaN cladding layer is grown in MOCVD at the growth temperature of 790 ℃ and the growth pressure of 200torr. When growing InAlGaN coating layer, NH is introduced into MOCVD reaction chamber 3 As a source of N; with N 2 As a carrier gas, TMAl is introduced as an Al source, TMIn is introduced as an In source, and TEGa is introduced as a Ga source.
The preparation method of each quantum barrier layer comprises the following steps:
(i) Growing an N-GaN layer;
specifically, an N-GaN layer grows in MOCVD at the growth temperature of 880 ℃ and the growth pressure of 300torr; during growth, NH is introduced into the MOCVD reaction chamber 3 As a source of N, siH is introduced 4 As N-type doping source; with H 2 And N 2 As carrier gas, TEGa was introduced as Ga source.
(ii) Growing an AlGaN layer on the N-GaN layer;
specifically, an AlGaN layer grows in MOCVD at the growth temperature of 880 ℃ and the growth pressure of 300torr; during growth, NH is introduced into the MOCVD reaction chamber 3 As N source, with H 2 And N 2 As a carrier gas, TMAl was introduced as an Al source, and TEGa was introduced as a Ga source.
(iii) And (ii) repeating the steps (i) and (ii) periodically until the quantum barrier layer is obtained.
(6) Growing an electron blocking layer on the active layer;
specifically, MOCVD is adopted to periodically grow Al a Ga 1-a N layer and In b Ga 1-b N layer as electron blocking layer, wherein Al a Ga 1-a The growth temperature of the N layer is 950 ℃ and the growth pressure is 300torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As N source, with N 2 And H 2 As carrier gas, TMAl is introduced as Al source, and TMGa is introduced as Ga source. In b Ga 1-b The growth temperature of the N layer is 950 ℃ and the growth pressure is 300torr. During growth, NH is introduced into the MOCVD reaction chamber 3 As N source, with N 2 And H 2 As a carrier gas, TMIn is introduced as an In source, and TMGa is introduced as a Ga source.
(7) Growing a P-type GaN layer on the electron blocking layer;
specifically, an MOCVD is adopted to grow a P-GaN layer, the growth temperature is 850 ℃, and the growth pressure is 200torr; during growth, NH is introduced into the MOCVD reaction chamber 3 As N source, cp is introduced 2 Mg is used as a P-type doping source; with H 2 And N 2 As carrier gas, TMGa was fed as Ga source.
Comparative example 1
This comparative example provides a green light emitting diode epitaxial wafer, which is different from example 1 In that the quantum well layer is an InGaN layer, the In component ratio is 0.3, the growth temperature is 650 to 700 ℃, and the growth pressure is 200torr.
Comparative example 2
This comparative example provides a green light emitting diode epitaxial wafer, which is different from example 1 in that an InN layer having a thickness of 15nm is provided in the quantum well layer 51, and the InN layer is not etched in the manufacturing method.
Comparative example 3
This comparative example provides a green light emitting diode epitaxial wafer, which is different from example 1 in that InN nanorods 511 are not included in the quantum well layer 51. Accordingly, in the production method, the production step of the layer is not provided, and the rest is the same as in example 1.
Comparative example 4
This comparative example provides a green light emitting diode epitaxial wafer, which is different from example 1 in that the InGaN cladding layer 512 is not included in the quantum well layer 51. Accordingly, in the production method, the production step of the layer is not provided, and the rest is the same as in example 1.
The green light emitting diodes obtained in examples 1 to 3 and comparative examples 1 to 4 were tested by the following specific test methods:
(1) The prepared epitaxial wafer is measured for the luminescence wavelength and the luminescence uniformity by an IM-1130 type PL spectrometer;
(2) Preparing the epitaxial wafer into a chip with a vertical structure of 5mil multiplied by 7mil, and testing the luminous brightness of the chip;
the specific results are as follows:
as can be seen from the table, when the conventional quantum well layer (comparative example 1) was changed to the quantum well layer structure of the present invention, the light emission efficiency and the wavelength uniformity were both significantly improved. Furthermore, as can be seen from the comparison between example 1 and comparative examples 2 to 4, when the quantum well layer structure in the present application is changed, it is difficult to effectively achieve the effects of improving the light emission efficiency and the wavelength uniformity.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.
Claims (10)
1. A green light emitting diode epitaxial wafer comprises a substrate, and a buffer layer, an intrinsic GaN layer, an N-type GaN layer, an active layer, an electronic barrier layer and a P-type GaN layer which are sequentially arranged on the substrate, wherein the active layer comprises a plurality of quantum well layers and quantum barrier layers which are alternately stacked; wherein each quantum well layer comprises a plurality of InN nanorods and an InGaN cladding layer wrapped on the InN nanorods.
2. The green light emitting diode epitaxial wafer as claimed In claim 1, wherein the In component content In each InN nanorod is 0.4-0.6, and the In component content In the InGaN cladding layer is 0.2-0.4.
3. The green light emitting diode epitaxial wafer as claimed In claim 1 or 2, wherein an InAlGaN cladding layer is further provided on the InGaN cladding layer, the content of In component In the InAlGaN cladding layer is 0.05-0.2, and the content of al component is 0.01-0.05;
the content of the In component In each InN nanorod is 0.45-0.65, and the content of the In component In the InGaN cladding layer is 0.25-0.4.
4. The green light emitting diode epitaxial wafer of claim 3, wherein the InN nanorods have a diameter of 5nm to 100nm, a length of 5nm to 20nm, and a spacing between adjacent InN nanorods of 5nm to 50nm;
the thickness of the InGaN coating layer is 1nm-3nm, and the thickness of the InAlGaN coating layer is 1nm-3nm.
5. The green light emitting diode epitaxial wafer of claim 1, wherein the quantum barrier layer is of a periodic structure, each period comprises an N-GaN layer and an AlGaN layer which are sequentially stacked, and the period number of the quantum barrier layer is not less than 2.
6. The green light emitting diode epitaxial wafer as claimed in claim 5, wherein the number of cycles of the quantum barrier layer is 3 to 6, the thickness of the single N-GaN layer is 1nm to 3nm, and the doping concentration is 1 x 10 15 cm -3 -1×10 16 cm -3 (ii) a The thickness of each AlGaN layer is 1nm-3nm, and the content of Al component is 0.1-0.5.
7. A method for preparing a green light emitting diode epitaxial wafer, which is used for preparing the green light emitting diode according to any one of claims 1 to 6, and comprises the following steps:
providing a substrate, and growing a buffer layer, an intrinsic GaN layer, an N-type GaN layer, an active layer, an electron barrier layer and a P-type GaN layer on the substrate in sequence, wherein the active layer comprises a plurality of quantum well layers and quantum barrier layers which are alternately stacked; each quantum well layer comprises a plurality of InN nanorods and an InGaN coating layer wrapped on the InN nanorods;
the preparation method of the InN nanorod comprises the following steps: and growing an InN layer, and etching to form a plurality of InN nanorods.
8. The method according to claim 7, wherein the InN layer is grown at a temperature of 700-750 deg.C and a growth pressure of 100-500torr, and the carrier gas used during growth is nitrogen or argon;
the growth temperature of the InGaN cladding layer is 750-770 ℃, the growth pressure is 100-500torr, and the carrier gas used in growth is nitrogen or argon.
9. The method for preparing the epitaxial wafer of the green light emitting diode of claim 7, wherein the quantum well layer further comprises an InAlGaN cladding layer disposed on the InGaN cladding layer, the InAlGaN cladding layer has a growth temperature of 770 ℃ to 800 ℃, a growth pressure of 100torr to 500torr, and a carrier gas used during growth is nitrogen or argon;
the quantum barrier layer is of a periodic structure, and each period comprises an N-GaN layer and an AlGaN layer which are sequentially stacked; the growth temperature of the N-GaN layer is 850-900 ℃, and the growth pressure is 100-500 torr;
the growth temperature of the AlGaN layer is 850-900 ℃, and the growth pressure is 100-500torr.
10. A green light emitting diode comprising the green light emitting diode epitaxial wafer as claimed in any one of claims 1 to 6.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115775853A (en) * | 2023-02-10 | 2023-03-10 | 江西兆驰半导体有限公司 | Light emitting diode epitaxial wafer, preparation method thereof and light emitting diode |
| CN116154060A (en) * | 2023-04-18 | 2023-05-23 | 江西兆驰半导体有限公司 | Yellow-green light LED epitaxial wafer, preparation method thereof and yellow-green light LED |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6558995B1 (en) * | 1998-07-31 | 2003-05-06 | Emory University | Holographic, laser-induced fabrication of indium nitride quantum wires and quantum dots |
| US20070108888A1 (en) * | 2005-11-11 | 2007-05-17 | National Chiao Tung University | Nanoparticle structure and manufacturing process of multi-wavelength light emitting device |
| CN101821861A (en) * | 2007-10-12 | 2010-09-01 | 新加坡科技研究局 | Fabrication of phosphor free red and white nitride-based leds |
| US20110241042A1 (en) * | 2010-04-02 | 2011-10-06 | Miin-Jang Chen | Nanocrystal-based optoelectronic device and method of fabricating the same |
| CN102244162A (en) * | 2011-07-14 | 2011-11-16 | 北京燕园中镓半导体工程研发中心有限公司 | Method for preparing light emitting diode |
| CN105428478A (en) * | 2015-11-24 | 2016-03-23 | 湘能华磊光电股份有限公司 | LED (Light Emitting Diode) epitaxial wafer and preparation method therefor |
| CN105932123A (en) * | 2016-05-18 | 2016-09-07 | 扬州中科半导体照明有限公司 | Nitride light-emitting diode epitaxial wafer with low-temperature AlInN insertion barrier layer, and production technology for nitride light-emitting diode epitaxial wafer |
| CN107170862A (en) * | 2017-06-08 | 2017-09-15 | 中国科学院半导体研究所 | A kind of non-polar plane light emitting diode with quantum dots and preparation method thereof |
| CN108807631A (en) * | 2018-05-03 | 2018-11-13 | 五邑大学 | A kind of LED epitaxial wafer and preparation method thereof of double mirror surface structures |
| CN112366258A (en) * | 2020-09-29 | 2021-02-12 | 华灿光电（浙江）有限公司 | Ultraviolet light-emitting diode epitaxial wafer and manufacturing method thereof |
| CN114242856A (en) * | 2022-02-24 | 2022-03-25 | 江西兆驰半导体有限公司 | Green light emitting diode epitaxial wafer and preparation method thereof |
-
2022
- 2022-11-14 CN CN202211417303.4A patent/CN115458651B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6558995B1 (en) * | 1998-07-31 | 2003-05-06 | Emory University | Holographic, laser-induced fabrication of indium nitride quantum wires and quantum dots |
| US20070108888A1 (en) * | 2005-11-11 | 2007-05-17 | National Chiao Tung University | Nanoparticle structure and manufacturing process of multi-wavelength light emitting device |
| CN101821861A (en) * | 2007-10-12 | 2010-09-01 | 新加坡科技研究局 | Fabrication of phosphor free red and white nitride-based leds |
| US20110241042A1 (en) * | 2010-04-02 | 2011-10-06 | Miin-Jang Chen | Nanocrystal-based optoelectronic device and method of fabricating the same |
| CN102244162A (en) * | 2011-07-14 | 2011-11-16 | 北京燕园中镓半导体工程研发中心有限公司 | Method for preparing light emitting diode |
| CN105428478A (en) * | 2015-11-24 | 2016-03-23 | 湘能华磊光电股份有限公司 | LED (Light Emitting Diode) epitaxial wafer and preparation method therefor |
| CN105932123A (en) * | 2016-05-18 | 2016-09-07 | 扬州中科半导体照明有限公司 | Nitride light-emitting diode epitaxial wafer with low-temperature AlInN insertion barrier layer, and production technology for nitride light-emitting diode epitaxial wafer |
| CN107170862A (en) * | 2017-06-08 | 2017-09-15 | 中国科学院半导体研究所 | A kind of non-polar plane light emitting diode with quantum dots and preparation method thereof |
| CN108807631A (en) * | 2018-05-03 | 2018-11-13 | 五邑大学 | A kind of LED epitaxial wafer and preparation method thereof of double mirror surface structures |
| CN112366258A (en) * | 2020-09-29 | 2021-02-12 | 华灿光电（浙江）有限公司 | Ultraviolet light-emitting diode epitaxial wafer and manufacturing method thereof |
| CN114242856A (en) * | 2022-02-24 | 2022-03-25 | 江西兆驰半导体有限公司 | Green light emitting diode epitaxial wafer and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 黄华茂等: "纳米柱高度对GaN基绿光LED光致发光谱的影响", 《发光学报》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115775853A (en) * | 2023-02-10 | 2023-03-10 | 江西兆驰半导体有限公司 | Light emitting diode epitaxial wafer, preparation method thereof and light emitting diode |
| CN115775853B (en) * | 2023-02-10 | 2023-05-16 | 江西兆驰半导体有限公司 | Light-emitting diode epitaxial wafer, preparation method thereof and light-emitting diode |
| CN116154060A (en) * | 2023-04-18 | 2023-05-23 | 江西兆驰半导体有限公司 | Yellow-green light LED epitaxial wafer, preparation method thereof and yellow-green light LED |
| CN116154060B (en) * | 2023-04-18 | 2023-06-23 | 江西兆驰半导体有限公司 | Yellow-green light LED epitaxial wafer, preparation method thereof and yellow-green light LED |
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