LED epitaxial wafers and their fabrication methods, LEDs

Abstract

This invention discloses a light-emitting diode (LED) epitaxial wafer and its fabrication method. The LED epitaxial wafer includes a substrate and, sequentially stacked on the substrate, a buffer layer, an undoped GaN layer, an N-type GaN layer, a composite insertion layer, a multiple quantum well layer, an electron blocking layer, and a P-type GaN layer. The composite insertion layer includes, sequentially stacked on the N-type GaN layer, a BN layer, a BInN layer, and a weakly P-type nitride layer. The LED fabricated by this invention can improve the crystal quality of the multiple quantum well layer and alleviate the piezoelectric polarization of the multiple quantum well layer, thereby improving the luminous efficiency of the LED epitaxial wafer.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a light-emitting diode epitaxial wafer and its fabrication method, and a light-emitting diode. Background Technology

[0002] Semiconductor lighting products, represented by GaN-based LEDs, have been widely used in backlighting, commercial lighting, landscape lighting, outdoor lighting, indoor lighting, and displays. The most significant advantage of LED light sources is energy saving; currently, the luminous efficiency of commercially available LED lamps generally exceeds 150 lm / W. Furthermore, due to their small size, fast response, and simple control, LEDs have great potential for integrability and intelligent lighting. In addition, LEDs also offer advantages such as being environmentally friendly, noiseless, flicker-free, long-lasting, highly adaptable, and highly reliable.

[0003] Traditional LED structures include a substrate, a buffer layer, an undoped GaN layer, an N-type GaN layer, a multiple quantum well layer, an electron blocking layer, and a P-type GaN layer. Among these, the InGaN quantum well layer in the multiple quantum well layer has a high In content, resulting in significant mismatch stress between the InGaN quantum well layer and the N-type GaN layer. This makes it difficult for In to incorporate into the InGaN quantum well layer. Simultaneously, the mismatch stress also leads to the generation of numerous defects, increasing nonradiative recombination in the quantum well layer. Furthermore, the mismatch stress causes the generation of a polarization electric field, reducing the spatial overlap of the electron-hole wavefunction and luminous efficiency, thus decreasing the luminous efficiency of the multiple quantum well layer. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a light-emitting diode epitaxial wafer that can improve the crystal quality of the multi-quantum-well layer, alleviate the piezoelectric polarization of the multi-quantum-well layer, and thus improve the luminous efficiency of the light-emitting diode epitaxial wafer.

[0005] The technical problem to be solved by the present invention is to provide a method for preparing an epitaxial wafer of a light-emitting diode, which is simple in process and produces an epitaxial wafer of a light-emitting diode with high luminous efficiency.

[0006] To achieve the above-mentioned technical effects, the present invention provides a light-emitting diode epitaxial wafer, comprising a substrate and a buffer layer, an undoped GaN layer, an N-type GaN layer, a composite insertion layer, a multiple quantum well layer, an electron blocking layer and a P-type GaN layer sequentially stacked on the substrate;

[0007] The composite insertion layer includes a BN layer, a BInN layer, and a weak P-type nitride layer sequentially stacked on the N-type GaN layer;

[0008] The weak P-type nitride layer is at least one of the following: C-doped GaN layer, C-doped AlGaN layer, C-doped AlInGaN layer, C-doped AlN layer, C-doped InGaN layer, C-doped InN layer, and C-doped AlInN layer.

[0009] As an improvement to the above technical solution, the C doping concentration of the weak P-type nitride layer is 5 × 10⁻⁶. 16 cm -3 -5×10 18 cm -3 .

[0010] As an improvement to the above technical solution, the weak P-type nitride layer is a stacked structure composed of multiple of the following: C-doped GaN layer, C-doped AlGaN layer, C-doped AlInGaN layer, C-doped AlN layer, C-doped InGaN layer, C-doped InN layer, and C-doped AlInN layer.

[0011] As an improvement to the above technical solution, the thickness of the BN layer is 1nm-100nm, the thickness of the BInN layer is 0.1nm-10nm, and the thickness of the weak P-type nitride layer is 1nm-100nm.

[0012] As an improvement to the above technical solution, the BN layer is a Si-doped BN layer with a Si doping concentration of 1×10⁻⁶. 17 cm -3 -1×10 19 cm -3 .

[0013] As an improvement to the above technical solution, the proportion of B component in the BInN layer is 0.01-0.5%.

[0014] Accordingly, the present invention also discloses a method for preparing a light-emitting diode epitaxial wafer, which includes the following steps:

[0015] A substrate is provided on which a buffer layer, an undoped GaN layer, an N-type GaN layer, a composite insertion layer, a multiple quantum well layer, an electron blocking layer and a P-type GaN layer are sequentially grown.

[0016] The composite insertion layer includes a BN layer, a BInN layer, and a weak P-type nitride layer sequentially stacked on the N-type GaN layer;

[0017] The weak P-type nitride layer is at least one of the following: C-doped GaN layer, C-doped AlGaN layer, C-doped AlInGaN layer, C-doped AlN layer, C-doped InGaN layer, C-doped InN layer, and C-doped AlInN layer.

[0018] As an improvement to the above technical solution, the growth temperature of the composite insertion layer is 700℃-1000℃, and the growth pressure is 50Torr-500Torr.

[0019] As an improvement to the above technical solution, the growth atmosphere of the composite insertion layer is N2 and NH3, and the flow rate ratio of N2 to NH3 is 1:(1-10).

[0020] Accordingly, the present invention also discloses a light-emitting diode, including the above-mentioned light-emitting diode epitaxial wafer.

[0021] Implementing the embodiments of the present invention has the following beneficial effects:

[0022] This invention grows a composite insertion layer between an N-type GaN layer and a multi-quantum-well layer. The composite insertion layer comprises a BN layer, a BInN layer, and a weakly p-type nitride layer deposited sequentially. First, the BN layer, due to the small atomic radius of boron (B), can prevent dislocations caused by mismatch between the N-type GaN layer and the substrate from extending into the multi-quantum-well layer, thus improving the crystal quality of the multi-quantum-well layer. Second, the deposition of the BInN layer can alleviate the lattice mismatch between the N-type GaN layer and the InGaN quantum well layer, promoting the incorporation of In atoms in the InGaN quantum well layer, improving crystal quality, and enhancing the device's luminous efficiency. Finally, the deposition of the weakly p-type nitride layer generates a small amount of positive charge, which balances the polarization electric field caused by the large lattice mismatch between the InGaN quantum well layer and the AlGaN quantum barrier layer in the multi-quantum-well layer, increasing the spatial overlap of the electron-hole wavefunction and improving the luminous efficiency of the multi-quantum-well layer. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the light-emitting diode epitaxial wafer provided in an embodiment of the present invention;

[0024] Figure 2 This is a flowchart of the method for fabricating a light-emitting diode epitaxial wafer provided in an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments.

[0026] like Figure 1 As shown, an embodiment of the present invention provides a light-emitting diode epitaxial wafer, including a substrate 1 and a buffer layer 2, an undoped GaN layer 3, an N-type GaN layer 4, a composite insertion layer 5, a multiple quantum well layer 6, an electron blocking layer 7, and a P-type GaN layer 8 sequentially stacked on the substrate 1.

[0027] The composite insertion layer 5 includes a BN layer, a BInN layer, and a weak P-type nitride layer sequentially stacked on the N-type GaN layer 4.

[0028] The weak p-type nitride layer is at least one of C-doped GaN, C-doped AlGaN, C-doped AlInGaN, C-doped AlN, C-doped InGaN, C-doped InN, and C-doped AlInN. After C-doping the nitride, a p-type hole concentration of 5 × 10⁻⁶ is formed. 15 cm -3 -5×10 17 cm -3 The weak p-type nitride layer.

[0029] First, the GaN epitaxial layer deposited on the substrate is a heteroepitaxial layer, with a significant difference in lattice constant between the substrate and GaN, resulting in a large number of dislocations in the GaN epitaxial layer. The small radius of boron atoms in the bN layer allows the growth of a bN layer on the N-type GaN layer 4 to prevent dislocations from extending further into the multi-quantum-well layer 6, thereby improving the crystal quality of the multi-quantum-well layer 6. Second, the significant lattice mismatch between the N-type GaN layer 4 and the InGaN quantum well layer in the multi-quantum-well layer 6 creates substantial mismatch stress. Depositing a bInN layer promotes the incorporation of indium atoms in the InGaN quantum well layer, improving crystal quality and enhancing the device's luminous efficiency. Finally, the significant lattice mismatch between the InGaN quantum well layer and the AlGaN quantum barrier layer in the multi-quantum-well layer 6 leads to the generation of a polarization electric field, causing a decrease in the luminous efficiency of the multi-quantum-well layer 6. Depositing a weak p-type nitride layer can generate a small amount of positive charge, thereby balancing the polarization electric field of the multi-quantum-well layer 6, increasing the spatial overlap of the electron-hole wavefunction, and improving the luminous efficiency of the multi-quantum-well layer.

[0030] In one embodiment, the doping concentration of the weak p-type nitride layer is 5 × 10⁻⁶. 16 cm -3 -5×10 18 cm -3 If the doping concentration of the weak p-type nitride layer is < 5 × 10⁻⁶ 16 cm -3 It cannot provide positive charge if the doping concentration of the weak p-type nitride layer is >5×10⁻⁶. 18 cm -3 This would reduce the lattice quality. For example, the doping concentration of a weak p-type nitride layer is 5 × 10⁻⁶. 16 cm -3 1×10 17 cm -3 5×10 17 cm -3 1×10 18 cm -3 Or 5×10 18 cm -3 However, it is not limited to this.

[0031] In one embodiment, the weakly p-type nitride layer is a stacked structure composed of multiple elements selected from C-doped GaN, C-doped AlGaN, C-doped AlInGaN, C-doped AlN, C-doped InGaN, C-doped InN, and C-doped AlInN layers. The C doping primarily originates from the decomposition of the source gas, and the doping concentration is controlled by adjusting the growth conditions.

[0032] In one embodiment, the thickness of the BN layer is 1 nm-100 nm. If the thickness of the BN layer is less than 1 nm, it cannot prevent dislocation propagation; if the thickness of the BN layer is greater than 100 nm, it will cause a decrease in lattice quality. The thickness of the BinN layer is 0.1 nm-10 nm. If the thickness of the BinN layer is less than 0.1 nm, it is not conducive to the incorporation of In atoms into the InGaN quantum well; if the thickness of the BinN layer is greater than 10 nm, it is not conducive to mitigating lattice mismatch. The thickness of the weak p-type nitride layer is 1 nm-100 nm. If the thickness of the weak p-type nitride layer is less than 1 nm, it cannot provide positive charge; if the thickness of the weak p-type nitride layer is greater than 100 nm, it will affect the migration of normal charge carriers.

[0033] In one embodiment, the BN layer is a Si-doped BN layer with a Si doping concentration of 1×10⁻⁶. 17 cm -3 -1×10 19 cm -3 For example, the Si doping concentration of the BN layer is 1×10⁻⁶. 17 cm -3 5×10 17 cm -3 1×10 18 cm -3 5×10 18 cm -3 Or 1×10 19 cm -3 However, this is not the only factor. The Si-doped BN layer has a lower deposition temperature, which can release the thermal expansion stress of the high-temperature deposited N-type GaN layer. Moreover, Si doping can prevent the bandgap of BN from being too large, thereby avoiding the voltage rise problem caused by an excessively high potential barrier.

[0034] In one embodiment, the proportion of the B component in the BInN layer is 0.01-0.5. By adjusting the ratio of the B component to the In component in the BInN layer, the mismatch stress in the active region is buffered. For example, the proportion of the B component in the BInN layer is 0.01, 0.05, 0.1, 0.3, 0.4, or 0.5, but is not limited thereto.

[0035] In addition to the aforementioned composite insert layer, the other layered structures of the present invention have the following characteristics:

[0036] In one embodiment, the substrate 1 is one of a sapphire substrate, a SiO2 / sapphire composite substrate, a silicon substrate, a silicon carbide substrate, a gallium nitride substrate, and a zinc oxide substrate. Preferably, the substrate 1 is a sapphire substrate.

[0037] In one embodiment, the buffer layer 2 is an AlGaN buffer layer or an AlN buffer layer. Preferably, the nucleation layer 2 is an AlN buffer layer, and the thickness of the buffer layer 2 is 10nm-50nm.

[0038] In one embodiment, the thickness of the undoped GaN layer 3 is 1 μm-5 μm.

[0039] In one embodiment, the thickness of the N-type GaN layer 4 is 2μm-3μm, and the N-type doping can be Si doping with a Si doping concentration of 1×10⁻⁶. 19 cm -3 -5×10 19 cm -3 .

[0040] In one embodiment, the multi-quantum-well layer 6 comprises periodically stacked InGaN quantum well layers and AlGaN quantum barrier layers, with a stacking period of 6-12. The InGaN quantum well layer has a thickness of 2nm-5nm and an In composition of 0.1-0.3; the AlGaN quantum barrier layer has a thickness of 5nm-15nm and an Al composition of 0.01-0.1.

[0041] In one embodiment, the electron blocking layer 7 is an AlInGaN layer with a thickness of 10nm-40nm, wherein the Al component accounts for 0.01-0.1% and the In component accounts for 0.01-0.2%.

[0042] In one embodiment, the thickness of the p-type GaN layer 8 is 10nm-50nm, and the p-type doping can be Mg doping with a Mg doping concentration of 1×10⁻⁶. 19 cm -3 -1×10 21 cm -3 .

[0043] Correspondingly, such as Figure 2 As shown, the present invention also provides a method for fabricating a light-emitting diode epitaxial wafer, comprising the following steps:

[0044] S100 provides a substrate:

[0045] A sapphire substrate was selected and loaded into the MOCVD chamber. The reaction chamber temperature was controlled at 1000℃-1200℃ and the pressure at 200Torr-600Torr. The sapphire substrate was subjected to high-temperature annealing for 5-8 minutes in an H2 atmosphere to clean the particles and oxides on the surface of the sapphire substrate.

[0046] S200 growth buffer layer:

[0047] PVD growth is employed, with sputtering temperature controlled at 600℃-900℃, sputtering power at 1500W-3000W, target material being pure aluminum (99.999% purity), and sputtering reaction gas being a mixture of N2 and Ar.

[0048] In one implementation, it further includes:

[0049] S300 pre-treats the substrate with the deposited buffer layer:

[0050] The substrate with the buffer layer deposited is transferred into MOCVD and pretreated in H2 atmosphere for 1 min-10 min at a temperature of 1000℃-1200℃, and then nitrided.

[0051] S400 growth of undoped GaN layers:

[0052] MOCVD growth was employed, with the reaction chamber temperature controlled at 1050℃-1200℃ and the pressure at 100Torr-600Torr. NH3 was introduced as the N source, N2 and H2 were introduced as the carrier gas, and TMGa was introduced as the Ga source.

[0053] S500 growth of N-type GaN layers:

[0054] MOCVD growth was employed, with the reaction chamber temperature controlled at 1050℃-1200℃ and the pressure at 100Torr-600Torr. NH3 was introduced as the N source, N2 and H2 as the carrier gas, TMGa as the Ga source, and SiH4 as the doping source.

[0055] The S600 growth composite insertion layer, specifically, in one embodiment, includes the following steps:

[0056] S601 BN layer growth:

[0057] MOCVD growth was employed, with the reaction chamber temperature controlled at 700℃-1000℃ and the pressure at 50Torr-100Torr. NH3 was introduced as the nitrogen source, N2 as the carrier gas, and TEB as the nitrogen source. The flow ratio of N2 to NH3 was 1:(1-10).

[0058] S602 for growing BInN layers:

[0059] MOCVD growth was used, with the reaction chamber temperature controlled at 700℃-1000℃ and the pressure at 50Torr-100Torr. NH3 was introduced as the N source, N2 as the carrier gas, TEB as the B source, and TMIn as the In source. The flow ratio of N2 to NH3 was 1:(1-10).

[0060] S603 grows a weak p-type nitride layer:

[0061] MOCVD growth was used, with the reaction chamber temperature controlled at 700-1000℃ and the pressure at 50-500 Torr. NH3 was introduced as the N source, N2 as the carrier gas, and one or more of the following sources were introduced: Ga (TEGa), In (TMIn), Al (TMAl), and B (TEB). The flow rate ratio of N2 to NH3 was 1:(1-10).

[0062] S700 growth of multiple quantum well layers:

[0063] MOCVD growth was employed, with the reaction chamber temperature controlled at 790℃-810℃ and the pressure at 50Torr-300Torr. NH3 was introduced as the N source, N2 as the carrier gas, TEGa as the Ga source, and TMIn as the In source to grow an InGaN quantum well layer. The reaction chamber temperature was controlled at 800℃-900℃, while maintaining constant pressure. NH3 was introduced as the N source, N2 and H2 as the carrier gases, TEGa as the Ga source, and TMAl as the Al source to grow an AlGaN quantum barrier layer. InGaN quantum well layers and AlGaN quantum barrier layers were then repeatedly stacked and periodically grown.

[0064] S800 electron blocking layer growth:

[0065] MOCVD growth was employed, with the reaction chamber temperature controlled at 900℃-1000℃ and the pressure at 100Torr-300Torr. NH3 was introduced as the N source, N2 and H2 as the carrier gas, TMGa as the Ga source, TMAl as the Al source, and TMIn as the In source.

[0066] S900 growth of P-type GaN layers:

[0067] MOCVD growth was employed, with the reaction chamber temperature controlled at 900℃-1050℃ and the pressure at 100Torr-600Torr. NH3 was introduced as the N source, N2 and H2 as the carrier gas, TMGa as the Ga source, and CP2Mg as the doping source.

[0068] The present invention will be further illustrated below with specific embodiments.

[0069] Example 1

[0070] This embodiment provides a light-emitting diode epitaxial wafer, including a substrate and a buffer layer, an undoped GaN layer, an N-type GaN layer, a composite insertion layer, a multiple quantum well layer, an electron blocking layer and a P-type GaN layer sequentially stacked on the substrate.

[0071] The substrate is a sapphire substrate.

[0072] The buffer layer is an AlN buffer layer with a thickness of 15nm.

[0073] The thickness of the undoped GaN layer is 2 μm.

[0074] The thickness of the N-type GaN layer is 2 μm, and the Si doping concentration is 2.5 × 10⁻⁶. 19 cm -3 .

[0075] The composite insertion layer consists of a BN layer, a BInN layer, and a weak p-type nitride layer. The BN layer is 25 nm thick, and the Si doping concentration is 6 × 10⁻⁶. 18 cm -3 The BInN layer is 3 nm thick with a boron content of 0.1%. The weak p-type nitride layer is a C-doped AlInGaN layer with a thickness of 55 nm and a C doping concentration of 3 × 10⁻⁶. 17 cm -3 .

[0076] The multiple quantum well layer consists of alternating layers of InGaN quantum wells and AlGaN quantum barriers, with a stacking period of 10. The InGaN quantum well layer is 3.5 nm thick with an In content of 0.2%; the AlGaN quantum barrier layer is 9.8 nm thick with an Al content of 0.05%.

[0077] The electron blocking layer is an AlInGaN layer with a thickness of 15 nm, an Al content of 0.05%, and an In content of 0.08%.

[0078] The thickness of the p-type GaN layer is 15 nm, and the Mg doping concentration is 2 × 10⁻⁶. 20 cm -3 .

[0079] The above-mentioned method for fabricating an epitaxial wafer of a light-emitting diode includes the following steps:

[0080] S100 provides a substrate:

[0081] A sapphire substrate was selected and loaded into the MOCVD chamber. The reaction chamber temperature was controlled at 1100℃ and the pressure at 250 Torr. The sapphire substrate was subjected to high-temperature annealing for 6 minutes in an H2 atmosphere to clean the particles and oxides on the surface of the sapphire substrate.

[0082] S200 growth buffer layer:

[0083] PVD growth was employed, with sputtering temperature controlled at 750℃, sputtering power at 2000W, target material being pure aluminum (99.999% purity), and sputtering reaction gas being a mixture of N2 and Ar.

[0084] S300 pre-treats the substrate with the deposited buffer layer:

[0085] The substrate with the buffer layer deposited was transferred into MOCVD and pretreated in H2 atmosphere for 6 min at a temperature of 1100℃, and then nitrided.

[0086] S400 growth of undoped GaN layers:

[0087] MOCVD growth was employed, with the reaction chamber temperature controlled at 1100℃ and the pressure at 150 Torr. NH3 was introduced as the N source, N2 and H2 were introduced as the carrier gas, and TMGa was introduced as the Ga source.

[0088] S500 growth of N-type GaN layers:

[0089] MOCVD growth was employed, with the reaction chamber temperature controlled at 1120℃ and the pressure at 200 Torr. NH3 was introduced as the N source, N2 and H2 as the carrier gas, TMGa as the Ga source, and SiH4 as the doping source.

[0090] The S600 composite insertion layer is grown, specifically including the following steps:

[0091] S601 BN layer growth:

[0092] MOCVD growth was employed, with the reaction chamber temperature controlled at 850℃ and the pressure at 200 Torr. NH3 was introduced as the nitrogen source, N2 as the carrier gas, and TEB as the nitrogen source. The flow ratio of N2 to NH3 was 1:2.

[0093] S602 for growing BInN layers:

[0094] MOCVD growth was employed, with the reaction chamber temperature controlled at 850℃ and the pressure at 200 Torr. NH3 was introduced as the N source, N2 as the carrier gas, TEB as the B source, and TMIn as the In source. The flow ratio of N2 to NH3 was 1:2.

[0095] S603 grows a weak p-type nitride layer:

[0096] MOCVD growth was employed, with the reaction chamber temperature controlled at 850℃ and the pressure at 200 Torr. NH3 was introduced as the N source, N2 as the carrier gas, TEGa as the Ga and C source, TMIn as the In and C source, and TMAl as the Al and C source. The flow ratio of N2 to NH3 was 1:2.

[0097] S700 growth of multiple quantum well layers:

[0098] MOCVD growth was employed, with the reaction chamber temperature controlled at 795℃ and the pressure at 200 Torr. NH3 was introduced as the N source, N2 as the carrier gas, TEGa as the Ga source, and TMIn as the In source to grow an InGaN quantum well layer. The reaction chamber temperature was then controlled at 855℃, while maintaining constant pressure. NH3 was introduced as the N source, N2 and H2 as the carrier gases, TEGa as the Ga source, and TMAl as the Al source to grow an AlGaN quantum barrier layer. InGaN quantum well layers and AlGaN quantum barrier layers were then repeatedly stacked and periodically grown.

[0099] S800 electron blocking layer growth:

[0100] MOCVD growth was employed, with the reaction chamber temperature controlled at 965℃ and the pressure at 200 Torr. NH3 was introduced as the N source, N2 and H2 as the carrier gas, TMGa as the Ga source, TMAl as the Al source, and TMIn as the In source.

[0101] S900 growth of P-type GaN layers:

[0102] MOCVD growth was employed, with the reaction chamber temperature controlled at 985℃ and the pressure at 200 Torr. NH3 was introduced as the N source, N2 and H2 as the carrier gas, TMGa as the Ga source, and CP2Mg as the doping source.

[0103] Example 2

[0104] This embodiment provides a light-emitting diode epitaxial wafer, wherein the composite insertion layer includes a BN layer, a BinN layer, and a weakly p-type nitride layer. The thickness of the BN layer is 35 nm, and the Si doping concentration is 6 × 10⁻⁶. 18 cm -3 The BinN layer is 5 nm thick with a boron content of 0.1%. The weak p-type nitride layer is a C-doped AlGaN layer with a thickness of 65 nm and a C doping concentration of 3 × 10⁻⁶. 17 cm -3 Everything else is the same as in Example 1.

[0105] Example 3

[0106] This embodiment provides a light-emitting diode epitaxial wafer, wherein the composite insertion layer includes a BN layer, a BinN layer, and a weakly p-type nitride layer. The thickness of the BN layer is 15 nm, and the Si doping concentration is 6 × 10⁻⁶. 18 cm -3 The BInN layer is 2 nm thick with a boron content of 0.1%. The weak p-type nitride layer is a C-doped InGaN layer with a thickness of 25 nm and a C doping concentration of 3 × 10⁻⁶. 17 cm -3 Everything else is the same as in Example 1.

[0107] Example 4

[0108] This embodiment provides a light-emitting diode epitaxial wafer, wherein the composite insertion layer includes a BN layer, a BinN layer, and a weakly p-type nitride layer. The thickness of the BN layer is 25 nm, and the Si doping concentration is 1 × 10⁻⁶. 18 cm -3 The BInN layer is 3 nm thick with a boron content of 0.2%. The weak p-type nitride layer is a C-doped AlInGaN layer with a thickness of 55 nm and a C doping concentration of 1 × 10⁻⁶. 17 cm -3 Everything else is the same as in Example 1.

[0109] Example 5

[0110] This embodiment provides a light-emitting diode epitaxial wafer, wherein the composite insertion layer includes a BN layer, a BinN layer, and a weakly p-type nitride layer. The thickness of the BN layer is 25 nm, and the Si doping concentration is 6 × 10⁻⁶. 19 cm -3 The BInN layer is 3 nm thick with a boron content of 0.1%. The weak p-type nitride layer is a C-doped AlInGaN layer with a thickness of 55 nm and a C doping concentration of 5 × 10⁻⁶. 17 cm -3 Everything else is the same as in Example 1.

[0111] Example 6

[0112] This embodiment provides a light-emitting diode epitaxial wafer, wherein the composite insertion layer includes a BN layer, a BinN layer, and a weakly p-type nitride layer. The thickness of the BN layer is 25 nm, and the Si doping concentration is 6 × 10⁻⁶. 18 cm -3 The BInN layer is 3 nm thick, with a B component ratio of 0.1%. The weak p-type nitride layer is a stack of C-doped AlGaN and C-doped GaN layers. The C-doped AlGaN layer is 30 nm thick, and the C-doped GaN layer is 25 nm thick. The C doping concentration of both the C-doped AlGaN and C-doped GaN layers is 3 × 10⁻⁶. 17 cm -3Everything else is the same as in Example 1.

[0113] Comparative Example 1

[0114] This comparative example provides a light-emitting diode epitaxial wafer, which differs from Example 1 in that it does not include a composite insertion layer. Correspondingly, the fabrication method also excludes the step of fabricating the composite insertion layer. Everything else is the same as in Example 1.

[0115] Performance testing:

[0116] The LED epitaxial wafers obtained in Examples 1-6 and Comparative Example 1 were fabricated into 10mil×24mil chips, and their photoelectric performance was tested at 120mA / 60mA current. The luminous efficacy improvement of Examples 1-6 compared to Comparative Example 1 was calculated, and the results are shown in Table 1.

[0117] Table 1. Photoelectric performance test results of LED epitaxial wafers

[0118] Light effect enhancement Example 1 4.5％ Example 2 3％ Example 3 1.8％ Example 4 2.2％ Example 5 3.5％ Example 6 5％

[0119] As shown in Table 1, the composite insertion layer of the present invention can improve the luminous efficiency of light-emitting diodes by 1.8%-5% compared with traditional epitaxial structures, indicating that the composite insertion layer in the present invention can effectively improve the luminous efficiency of light-emitting diodes.

[0120] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A light-emitting diode epitaxial wafer, characterized in that, It includes a substrate and a buffer layer, an undoped GaN layer, an N-type GaN layer, a composite insertion layer, a multiple quantum well layer, an electron blocking layer and a P-type GaN layer sequentially stacked on the substrate; The composite insertion layer includes a BN layer, a BInN layer, and a weak P-type nitride layer sequentially stacked on the N-type GaN layer; The weak P-type nitride layer is a stacked structure composed of multiple of the following: C-doped GaN layer, C-doped AlGaN layer, C-doped AlInGaN layer, C-doped AlN layer, C-doped InGaN layer, C-doped InN layer, and C-doped AlInN layer. The C doping concentration of the weak P-type nitride layer is 5 × 10⁻⁶. 16 cm -3 -5×10 18 cm -3 .

2. The light-emitting diode epitaxial wafer as described in claim 1, characterized in that, The thickness of the BN layer is 1nm-100nm, the thickness of the BInN layer is 0.1nm-10nm, and the thickness of the weak p-type nitride layer is 1nm-100nm.

3. The light-emitting diode epitaxial wafer as described in claim 1, characterized in that, The BN layer is a Si-doped BN layer with a Si doping concentration of 1×10⁻⁶. 17 cm -3 -1×10 19 cm -3 .

4. The light-emitting diode epitaxial wafer as described in claim 1, characterized in that, The proportion of B component in the BInN layer is 0.01-0.5%.

5. A method for fabricating a light-emitting diode epitaxial wafer, used to fabricate a light-emitting diode epitaxial wafer as described in any one of claims 1-4, characterized in that, Includes the following steps: A substrate is provided on which a buffer layer, an undoped GaN layer, an N-type GaN layer, a composite insertion layer, a multiple quantum well layer, an electron blocking layer and a P-type GaN layer are sequentially grown. The composite insertion layer includes a BN layer, a BInN layer, and a weak P-type nitride layer sequentially stacked on the N-type GaN layer; The weak P-type nitride layer is a stacked structure composed of multiple of the following: C-doped GaN layer, C-doped AlGaN layer, C-doped AlInGaN layer, C-doped AlN layer, C-doped InGaN layer, C-doped InN layer, and C-doped AlInN layer. The C doping concentration of the weak P-type nitride layer is 5 × 10⁻⁶. 16 cm -3 -5×10 18 cm -3 .

6. The method for fabricating a light-emitting diode epitaxial wafer as described in claim 5, characterized in that, The growth temperature of the composite insertion layer is 700℃-1000℃, and the growth pressure is 50Torr-500Torr.

7. The method for fabricating a light-emitting diode epitaxial wafer as described in claim 5, characterized in that, The growth atmosphere of the composite insertion layer is N2 and NH3, and the flow rate ratio of N2 to NH3 is 1:(1-10).

8. A light-emitting diode, characterized in that, The light-emitting diode includes a light-emitting diode epitaxial wafer as described in any one of claims 1-4.

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