GaN-based light emitting diode epitaxial wafer and preparation method thereof, and GaN-based light emitting diode

Abstract

The application discloses a GaN-based light-emitting diode epitaxial wafer and a preparation method thereof and a GaN-based light-emitting diode, and relates to the field of semiconductor photoelectric devices. The GaN-based light-emitting diode epitaxial wafer comprises a substrate and a nucleation 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 arranged on the substrate in sequence; and the P-type semiconductor layer is a C / O co-doped P-type GaN thin film layer. By implementing the application, the brightness of the light-emitting diode can be improved, the anti-static capacity can be improved, and the surface roughness can be reduced.

Description

GaN-based light-emitting diode epitaxial wafers and their fabrication methods, GaN-based light-emitting diodes Technical Field

[0001] This invention relates to the field of semiconductor optoelectronic devices, and more particularly to a GaN-based light-emitting diode epitaxial wafer and its fabrication method, and a GaN-based light-emitting diode. Background Technology

[0002] Currently, GaN-based light-emitting diodes (LEDs) are widely used in solid-state lighting and display fields, attracting increasing attention. The epitaxial wafer is the main component of an LED. A traditional LED epitaxial wafer includes: a substrate and, sequentially grown on the substrate, a nucleation layer, an intrinsic GaN layer, an N-type semiconductor layer, a multiple quantum well layer, an electron blocking layer, and a P-type semiconductor layer. The P-type semiconductor layer, as the last grown capping layer and hole-providing layer, significantly affects the surface flatness of the epitaxial wafer, the luminous efficiency of the LED, and its anti-static capability.

[0003] P-type doped Mg readily forms Mg-H complexes, and the low activation rate of Mg results in insufficient hole concentration. To achieve a high hole concentration, high Mg doping concentrations are required. However, Mg has low solubility in GaN, and high-concentration Mg doping leads to decreased crystal quality and surface flatness, affecting the device's antistatic capability and luminous efficiency. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a GaN-based light-emitting diode epitaxial wafer and its preparation method, which can improve the luminous efficiency, antistatic capability and surface flatness of the light-emitting diode.

[0005] Another technical problem that this invention aims to solve is to provide a GaN-based light-emitting diode with high luminous efficiency.

[0006] To address the aforementioned problems, this invention discloses a GaN-based light-emitting diode epitaxial wafer, comprising a substrate and, sequentially disposed on the substrate, a nucleation layer, an intrinsic GaN layer, an N-type semiconductor layer, a multiple quantum well layer, an electron blocking layer, and a P-type semiconductor layer; wherein the P-type semiconductor layer is a C / O co-doped P-type GaN thin film layer.

[0007] As an improvement to the above technical solution, the C doping concentration in the C / O co-doped P-type GaN thin film layer is 5 × 10⁻⁶. 17 cm -3 -5×10 18 cm -3 The doping concentration of O is 1×10⁻⁶. 17 cm -3 -1×10 18 cm -3 .

[0008] As an improvement to the above technical solution, the P-type dopant element in the C / O co-doped P-type GaN thin film is Mg, and the Mg doping concentration is 5 × 10⁻⁶. 17 cm -3 -1×10 20 cm -3 The thickness of the C / O co-doped P-type GaN thin film is 5nm-50nm.

[0009] As an improvement to the above technical solution, the P-type semiconductor layer further includes an InN quantum dot layer, which is disposed between the electron blocking layer and the C / O co-doped P-type GaN thin film layer.

[0010] As an improvement to the above technical solution, the proportion of In component in the InN quantum dot layer is 0.1-0.5, and the thickness of the InN quantum dot layer is 1nm-5nm.

[0011] Accordingly, the present invention also discloses a method for preparing a GaN-based light-emitting diode epitaxial wafer, which includes:

[0012] A substrate is provided on which a nucleation layer, an intrinsic GaN layer, an N-type semiconductor layer, a multiple quantum well layer, an electron blocking layer, and a P-type semiconductor layer are sequentially grown; the P-type semiconductor layer is a C / O co-doped P-type GaN thin film layer.

[0013] As an improvement to the above technical solution, the growth method of the C / O co-doped P-type GaN thin film layer is as follows: the P-type GaN thin film layer is grown by MOCVD, the growth temperature is 900℃-1000℃, the growth pressure is 100 torr-300 torr, and the carrier gas used during growth is H2.

[0014] The p-type GaN thin film was annealed in an atmosphere of N2 and CO2, wherein the flow rate of N2 was 5 mL / min-30 mL / min, the flow rate of CO2 was 10 mL / min-50 mL / min, the annealing temperature was 500℃-800℃, the annealing pressure was 100 torr-500 torr, and the annealing time was 3 min-10 min.

[0015] As an improvement to the above technical solution, the P-type semiconductor layer further includes an InN quantum dot layer, which is disposed between the electron blocking layer and the C / O co-doped P-type GaN thin film layer.

[0016] As an improvement to the above technical solution, the growth temperature of the InN quantum dot layer is 700℃-800℃, the growth pressure is 200 torr-500 torr, and the carrier gas used during growth is N2.

[0017] Accordingly, the present invention also discloses a GaN-based light-emitting diode, which includes the above-mentioned GaN-based light-emitting diode epitaxial wafer.

[0018] Implementing this invention has the following beneficial effects:

[0019] 1. In the GaN-based light-emitting diode epitaxial wafer of the present invention, the P-type semiconductor layer is a C / O co-doped P-type GaN thin film layer. O has strong electronegativity, which is beneficial to reducing the generation of Ga vacancies in the P-type semiconductor material. C can act as an amphoteric dopant, which can also reduce Ga vacancy diffusion, thereby improving the lattice quality of the P-type semiconductor layer, which is beneficial to increasing the hole concentration and improving the surface flatness. In the C and O co-doping process, it is equivalent to an annealing process, which can redistribute Mg atoms, reduce defects, effectively increase the hole concentration and promote the expansion of charge carriers, thereby improving the antistatic ability and luminous efficiency.

[0020] 2. In the GaN-based light-emitting diode epitaxial wafer of the present invention, the P-type semiconductor layer further includes an InN quantum dot layer. The InN quantum dot layer is in close contact with the C / O co-doped P-type GaN thin film layer, allowing In atoms to easily penetrate into the C / O co-doped P-type GaN thin film layer, reducing the activation energy of Mg and thus increasing the hole concentration. In atoms diffuse into the C / O co-doped P-type GaN thin film layer, achieving better lattice quality than direct doping, and the In group is uniformly distributed, resulting in a more uniform carrier distribution and increased carrier expansion. The InN quantum dot layer can also act as a surface activator, altering the surface energy of the material and increasing the mobility of Mg atoms during the growth of the C / O co-doped P-type GaN thin film layer, resulting in a uniform distribution of Mg atoms and further increasing carrier expansion.

[0021] 3. In the GaN-based light-emitting diode epitaxial wafer of the present invention, the C / O co-doped P-type GaN thin film layer is grown using pure H2, which can significantly improve the lattice quality and surface flatness. Since P-type doped Mg atoms easily form Mg-H complexes, the resulting hole concentration is low. The Mg-H complexes can react with CO2 to break the Mg-H bonds, and H atoms react with O atoms to generate H2O and be discharged. This not only improves the lattice quality but also avoids the formation of Mg-H complexes from affecting the hole concentration. Attached Figure Description

[0022] Figure 1 is a schematic diagram of the structure of a GaN-based light-emitting diode epitaxial wafer in one embodiment of the present invention;

[0023] Figure 2 is a schematic diagram of the structure of a P-type semiconductor layer in one embodiment of the present invention;

[0024] Figure 3 is a schematic diagram of the structure of a P-type semiconductor layer in one embodiment of the present invention;

[0025] Figure 4 is a flowchart of a method for fabricating a GaN-based light-emitting diode epitaxial wafer according to an embodiment of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in further detail below.

[0027] Referring to Figures 1 and 2, the present invention discloses a light-emitting diode epitaxial wafer, comprising a substrate 1 and a nucleation layer 2, an intrinsic GaN layer 3, an N-type semiconductor layer 4, a multiple quantum well layer 5, an electron blocking layer 6, and a P-type semiconductor layer 7 sequentially disposed on the substrate 1.

[0028] Among them, the P-type semiconductor layer 7 is a C / O co-doped P-type GaN thin film layer 71. Based on this configuration, the strong electronegativity of O helps to reduce the generation of Ga vacancies in the P-type semiconductor material. C can act as an amphoteric dopant, which can also reduce Ga vacancy diffusion, thereby improving the lattice quality of the P-type semiconductor layer 7, which is beneficial to improving the high hole concentration and surface flatness. In the C and O co-doping process, it is equivalent to an annealing process, which can redistribute Mg atoms, reduce defects, effectively increase hole concentration and promote carrier expansion, and improve antistatic ability and luminous efficiency.

[0029] Specifically, the C doping concentration in the C / O co-doped p-type GaN thin film layer 71 is 1×10⁻⁶. 16 cm -3 -8×10 18 cm -3 When the doping concentration of C is < 1 × 10 16 cm -3 It is difficult to effectively reduce the diffusion of Ga site holes; when the C doping concentration is >8×10 18 cm -3 If the hole concentration is too low, the luminescence efficiency will be affected. For example, the doping concentration of C is 2 × 10⁻⁶. 16 cm -3 4×10 16 cm -3 6×10 16 cm -3 8×10 16 cm -3 1×10 17 cm -3 3×10 17 cm -3 5×1017 cm -3 8×10 17 cm -3 2×10 18 cm -3 Or 4×10 18 cm -3 However, it is not limited to this. Preferably, the C doping concentration in the C / O co-doped p-type GaN thin film layer 71 is 5 × 10⁻⁶. 17 cm -3 -5×10 18 cm -3 .

[0030] The doping concentration of O is 8 × 10⁻⁶. 16 cm -3 -3×10 18 cm -3 When the doping concentration of O is < 8 × 10 16 cm -3 It is difficult to effectively reduce the generation of Ga vacancies in P-type semiconductor materials when the O doping concentration is >3×10⁻⁶. 18 cm -3 The preparation cost is relatively high. For example, the O doping concentration is 1 × 10⁻⁶. 17 cm -3 3×10 17 cm -3 5×10 17 cm -3 7×10 17 cm -3 9×10 17 cm -3 1×10 18 cm -3 Or 2×10 18 cm -3 However, it is not limited to this. Preferably, the O doping concentration is 1 × 10⁻⁶. 17 cm -3 -1×10 18 cm -3 .

[0031] Specifically, the P-type dopant element in the C / O co-doped P-type GaN thin film layer 71 is Mg, and the Mg doping concentration is 5 × 10⁻⁶. 17 cm -3 -5×10 20 cm -3 When the doping concentration of Mg is < 5 × 10 17 cm -3 Low hole concentration affects luminescence efficiency; when the doping concentration of Mg is > 5 × 10⁻⁶, the luminescence efficiency is affected. 20 cm -3This can lead to a decrease in lattice quality, an increase in defects, and a decline in antistatic properties. For example, the doping concentration of Mg is 6 × 10⁻⁶. 17 cm -3 8×10 17 cm -3 1×10 18 cm -3 2×10 18 cm -3 4×10 18 cm -3 6×10 18 cm -3 8×10 18 cm -3 1×10 19 cm -3 2×10 19 cm -3 4×10 19 cm -3 6×10 19 cm -3 1×10 20 cm -3 Or 5×10 20 cm -3 However, it is not limited to this. Preferably, the Mg doping concentration is 5 × 10⁻⁶. 17 cm -3 -1×10 20 cm -3 .

[0032] The thickness of the C / O co-doped P-type GaN thin film layer 71 is 1 nm to 80 nm. When its thickness is < 1 nm, it is difficult to effectively improve lattice quality, hole concentration, and luminous efficiency; when its thickness is > 80 nm, it will cause light absorption. For example, the thickness of the C / O co-doped P-type GaN thin film layer 71 is 5 nm, 7 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 50 nm, 60 nm, 70 nm, or 75 nm, but is not limited to these. Preferably, the thickness of the C / O co-doped P-type GaN thin film layer 71 is 5 nm to 50 nm.

[0033] Preferably, in one embodiment of the present invention, referring to Figures 1 and 3, the P-type semiconductor layer 7 further includes an InN quantum dot layer 72, which is disposed between the electron blocking layer 6 and the C / O co-doped P-type GaN thin film layer 71. Based on this arrangement, the InN quantum dot layer 72 is in close contact with the C / O co-doped P-type GaN thin film layer 71, allowing In atoms to easily penetrate the C / O co-doped P-type GaN thin film layer 71, reducing the activation energy of Mg and thus increasing the hole concentration. Diffusion allows In atoms to enter the C / O co-doped P-type GaN thin film layer 71, resulting in better lattice quality than direct doping, and a more uniform In distribution, leading to a more uniform carrier distribution and increased carrier expansion. The InN quantum dot layer 72 can also act as a surface activator, altering the surface energy of the material and increasing the mobility of Mg atoms during the growth of the C / O co-doped P-type GaN thin film layer 71, resulting in a uniform distribution of Mg atoms and further increasing carrier expansion.

[0034] Specifically, the proportion of In in the InN quantum dot layer 72 is 0.05-0.6%. When the proportion of In is <0.05, it is difficult to effectively reduce the activation energy of Mg; when the proportion of In is >0.6, it will introduce too many defects and reduce the lattice quality. For example, the proportion of In is 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, or 0.55, but is not limited thereto. Preferably, the proportion of In in the InN quantum dot layer 72 is 0.1-0.5.

[0035] The thickness of the InN quantum dot layer 72 is 0.5 nm to 7 nm. When its thickness is less than 0.5 nm, it cannot activate Mg atoms or uniformly distribute charge carriers; when its thickness is greater than 7 nm, it leads to a deterioration in lattice quality. For example, the thickness of the InN quantum dot layer 72 can be 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm, 4.5 nm, 5 nm, 5.5 nm, or 6 nm, but is not limited to these. Preferably, the thickness of the InN quantum dot layer 72 is 1 nm to 5 nm.

[0036] The substrate 1 can be a sapphire substrate, a silicon substrate, or a silicon carbide substrate, but is not limited to these.

[0037] The nucleation layer 2 may be an AlN layer and / or an AlGaN layer, but is not limited thereto. The thickness of the nucleation layer 2 is 20nm-100nm, with exemplary thicknesses of 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, or 90nm, but is not limited thereto.

[0038] The thickness of the intrinsic GaN layer 3 is 300nm-800nm, with examples of 350nm, 400nm, 450nm, 500nm, 550nm, 600nm, 650nm, 700nm or 750nm, but not limited to these.

[0039] The N-type semiconductor layer 4 is doped with Si, but is not limited to Si. The doping concentration of the N-type semiconductor layer 4 is 5 × 10⁻⁶. 18 cm -3 -1×10 19 cm -3 The thickness is 1μm-3μm.

[0040] Among them, the multi-quantum-well layer 5 consists of alternating stacked InGaN quantum well layers and GaN quantum barrier layers, with a stacking period of 3-15. The thickness of a single InGaN quantum well layer is 2nm-5nm, and the thickness of a single GaN quantum barrier layer is 6nm-15nm.

[0041] Among them, electron blocking layer 6 is Al c Ga 1-c N layers and In d Ga 1-d The structure consists of N alternating layers in a periodic pattern with a period number of 3-15; where c is 0.05-0.2 and d is 0.1-0.5. The electron blocking layer 6 has a thickness of 20nm-150nm.

[0042] Accordingly, referring to Figure 4, the present invention also discloses a method for preparing a GaN-based light-emitting diode epitaxial wafer, which is used to prepare the above-mentioned GaN-based light-emitting diode epitaxial wafer, and includes the following steps:

[0043] S100: Provides a substrate;

[0044] Specifically, the substrate can be a sapphire substrate, a silicon substrate, or a silicon carbide substrate, but is not limited to these. A sapphire substrate is preferred.

[0045] Preferably, in one embodiment of the present invention, the substrate is loaded into MOCVD and annealed at 1000℃-1200℃, 200 torr-600 torr, in a hydrogen atmosphere for 5 min-8 min to remove impurities such as particles and oxides from the substrate surface.

[0046] S200: Nucleation layer is grown on the substrate;

[0047] Specifically, an AlGaN layer can be grown using MOCVD or PVD, but is not limited to these methods. Preferably, the AlGaN layer is grown using MOCVD at a growth temperature of 500℃-700℃ and a growth pressure of 200 torr-400 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source; H2 and N2 are used as carrier gases; TMAl is introduced as the Al source; and TMGa is introduced as the Ga source.

[0048] S300: Intrinsic GaN layers are grown on the nucleation layer;

[0049] Specifically, intrinsic GaN layers were grown in MOCVD at a temperature of 1100℃-1150℃ and a pressure of 100 torr-500 torr. During growth, NH3 was introduced into the MOCVD reaction chamber as the N source; H2 and N2 were used as carrier gases, and TMGa was introduced as the Ga source.

[0050] S400: An N-type semiconductor layer is grown on an intrinsic GaN layer;

[0051] Specifically, an N-type semiconductor layer is grown in MOCVD at a temperature of 1100℃-1150℃ and a pressure of 100 torr-500 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, and SiH4 is introduced as the N-type doping source; H2 and N2 are used as carrier gases, and TMGa is introduced as the Ga source.

[0052] S500: A multi-quantum-well layer is grown on an N-type semiconductor layer;

[0053] Specifically, InGaN quantum well layers and GaN quantum barrier layers are periodically grown in MOCVD to form a multi-quantum well layer. The InGaN quantum well layer is grown at a temperature of 700℃-800℃ and a growth pressure of 100 torr-500 torr. During growth, NH3 is introduced as the N source, N2 as the carrier gas, TEGa as the Ga source, and TMIn as the In source in the MOCVD reaction chamber. The GaN quantum barrier layer is grown at a temperature of 800℃-900℃ and a growth pressure of 100 torr-500 torr. During growth, NH3 is introduced as the N source, H2 and N2 as the carrier gases, and TEGa as the Ga source in the MOCVD reaction chamber.

[0054] S600: An electron blocking layer is grown on a multi-quantum-well layer;

[0055] Specifically, Al is periodically grown in MOCVD. c Ga 1-c N layers and In d Ga 1-dThe N-layer acts as an electron-blocking layer. Al c Ga 1-c The N-layer growth temperature is 900℃-1000℃, and the growth pressure is 100 torr-500 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, N2 and H2 are used as carrier gases, TMAl is introduced as the Al source, and TMGa is introduced as the Ga source. d Ga 1-d The N-layer is grown at a temperature of 900℃-1000℃ and a growth pressure of 100 torr-500 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, N2 and H2 are used as carrier gases, TMIn is introduced as the In source, and TMGa is introduced as the Ga source.

[0056] S700: A P-type semiconductor layer is grown on an electron blocking layer;

[0057] Specifically, in one embodiment of the present invention, S700 includes:

[0058] S710: InN quantum dot layer grown on electron blocking layer;

[0059] Specifically, the InN quantum dot layer is grown in MOCVD under the same growth conditions as commonly used InN layers in the art. Preferably, in one embodiment of the invention, the InN quantum dot layer is grown at a temperature of 700°C-800°C and a growth pressure of 200 torr-500 torr. NH3 is introduced as the N source, and TMIn is introduced as the In source. N2 is used as the carrier gas during growth. Using a lower growth temperature and a higher growth pressure results in better crystal quality of the InN quantum dot layer; using pure N2 as the carrier gas is beneficial for the growth of the InN quantum dot layer.

[0060] S720: A C / O co-doped P-type GaN thin film layer is grown on an InN quantum dot layer;

[0061] Specifically, in one embodiment of the present invention, S720 includes:

[0062] S721: Growth of a P-type GaN thin film layer on an InN quantum dot layer;

[0063] Specifically, P-type GaN thin films were grown in MOCVD at a temperature of 900℃-1000℃ and a pressure of 100 torr-300 torr. TEGa was used as the Ga source, CP2Mg as the P-type doped Mg source, and NH3 as the N source. H2 was used as the carrier gas. The higher growth temperature and lower growth pressure improved the lattice quality and facilitated the leveling of the InN quantum dot layer. Using pure H2 as the carrier gas was beneficial for film growth, resulting in higher lattice quality and surface smoothness of the film layer.

[0064] S722: Annealing a P-type GaN thin film layer to obtain a C / O co-doped P-type GaN thin film layer;

[0065] Specifically, annealing can be performed in MOCVD or transferred to a rapid annealing furnace reaction chamber for annealing. Preferably, the p-type GaN thin film is transferred to the rapid annealing furnace reaction chamber for annealing. The annealing atmosphere is N2 and CO2, with an N2 flow rate of 5 mL / min-30 mL / min and a CO2 flow rate of 10 mL / min-50 mL / min. The annealing temperature is 500℃-800℃, the annealing pressure is 100 torr-500 torr, and the annealing time is 3 min-10 min. C / O co-doping of the p-type GaN thin film improves lattice quality and avoids the formation of Mg-H complexes that could affect hole concentration.

[0066] The present invention will be further described below with reference to specific embodiments:

[0067] Example 1

[0068] This embodiment provides a GaN-based light-emitting diode epitaxial wafer. Referring to Figures 1 and 2, it includes a substrate 1 and a nucleation layer 2, an intrinsic GaN layer 3, an N-type semiconductor layer 4, a multiple quantum well layer 5, an electron blocking layer 6, and a P-type semiconductor layer 7 sequentially disposed on the substrate 1.

[0069] In this design, substrate 1 is a sapphire substrate; nucleation layer 2 is an AlGaN layer with a thickness of 30 nm; intrinsic GaN layer 3 has a thickness of 400 nm; and the Si doping concentration in N-type semiconductor layer 4 is 7 × 10⁻⁶. 18 cm -3 Its thickness is 2μm.

[0070] Among them, the multi-quantum well layer 5 consists of alternating stacked InGaN quantum well layers and GaN quantum barrier layers, with a stacking period of 10. The thickness of a single InGaN quantum well layer is 3nm, and the thickness of a single GaN quantum barrier layer is 10nm.

[0071] Among them, electron blocking layer 6 is Al c Ga 1-cN layers (c = 0.12) and In d Ga 1-d A periodic structure with N alternating layers (d = 0.3) and a period number of 8, where a single Al c Ga 1-c The thickness of the N layer is 6nm, and a single In... d Ga 1-d The thickness of the N layer is 6 nm.

[0072] Among them, the P-type semiconductor layer 7 is a C / O co-doped P-type GaN thin film layer 71, with a C doping concentration of 1×10⁻⁶. 18 cm -3 The O doping concentration is 2 × 10⁻⁶. 17 cm -3 The Mg doping concentration is 5 × 10⁻⁶. 19 cm -3 The thickness is 7nm.

[0073] The method for fabricating the GaN-based light-emitting diode epitaxial wafer in this embodiment includes the following steps:

[0074] (1) Provide a substrate; load the substrate into MOCVD and anneal it at 1120℃, 400 torr, and hydrogen atmosphere for 6 min.

[0075] (2) Growing a nucleation layer on a substrate;

[0076] Specifically, the AlGaN layer was grown using MOCVD at a growth temperature of 620℃ and a growth pressure of 250 torr. During growth, NH3 was introduced into the MOCVD reaction chamber as the N source; H2 and N2 were used as carrier gases; TMAl was introduced as the Al source; and TMGa was introduced as the Ga source.

[0077] (3) Grow an intrinsic GaN layer on the nucleation layer;

[0078] Specifically, intrinsic GaN layers were grown using MOCVD at a growth temperature of 1100℃ and a growth pressure of 250 tor. During growth, NH3 was introduced into the MOCVD reaction chamber as the N source, and H2 and N2 were used as carrier gases, while TMGa was introduced as the Ga source.

[0079] (4) Grow an N-type semiconductor layer on the intrinsic GaN layer;

[0080] Specifically, an N-type semiconductor layer was grown using MOCVD at a growth temperature of 1120℃ and a growth pressure of 150 torr. During growth, NH3 was introduced into the MOCVD reaction chamber as an N source and SiH4 was introduced as an N-type doping source. H2 and N2 were used as carrier gases, and TMGa was introduced as a Ga source.

[0081] (5) Growing a multi-quantum-well layer on an N-type semiconductor layer;

[0082] Specifically, quantum well layers and quantum barrier layers are periodically grown in MOCVD to obtain multiple quantum well layers;

[0083] The quantum well layer is grown at a temperature of 750℃ and a growth pressure of 300 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, N2 is introduced as the carrier gas, TEGa is introduced as the Ga source, and TMIn is introduced as the In source. The quantum barrier layer is grown at a temperature of 820℃ and a growth pressure of 300 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, H2 and N2 are introduced as the carrier gases, and TEGa is introduced as the Ga source.

[0084] (6) An electron blocking layer is grown on the composite insertion layer;

[0085] Specifically, Al is periodically grown in MOCVD. c Ga 1-c N layers and In d Ga 1-d The N-layer acts as an electron-blocking layer. Al c Ga 1-c The N-layer was grown at a temperature of 950℃ and a growth pressure of 250 torr. During growth, NH3 was introduced into the MOCVD reaction chamber as the N source, N2 and H2 were used as carrier gases, TMAl was introduced as the Al source, and TMGa was introduced as the Ga source. d Ga 1-d The N-layer was grown at a temperature of 950℃ and a growth pressure of 250 torr. During growth, NH3 was introduced into the MOCVD reaction chamber as the N source, N2 and H2 were used as carrier gases, TMIn was introduced as the In source, and TMGa was introduced as the Ga source.

[0086] (7) Grow a P-type semiconductor layer on the electron blocking layer;

[0087] (I) Growth of a P-type GaN thin film on an electron blocking layer;

[0088] Specifically, a p-type GaN thin film was grown in MOCVD at a temperature of 900℃ and a pressure of 200 torr. During growth, TEGa was introduced as the Ga source, CP2Mg as the p-type doped Mg source, and NH3 as the N source into the MOCVD reaction chamber. H2 was used as the carrier gas during growth.

[0089] (II) Annealing the P-type GaN thin film layer to obtain a C / O co-doped P-type GaN thin film layer;

[0090] Specifically, the P-type GaN thin film layer was transferred to the reaction chamber of a rapid annealing furnace for annealing. The annealing atmosphere was N2 and CO2, with a flow rate of 15 mL / min for N2 and 20 mL / min for CO2. The annealing temperature was 600℃, the annealing pressure was 300 torr, and the annealing time was 5 min.

[0091] Example 2

[0092] This embodiment provides a GaN-based light-emitting diode epitaxial wafer. Referring to Figures 1 and 3, it includes a substrate 1 and a nucleation layer 2, an intrinsic GaN layer 3, an N-type semiconductor layer 4, a multiple quantum well layer 5, an electron blocking layer 6, and a P-type semiconductor layer 7 sequentially disposed on the substrate 1.

[0093] In this design, substrate 1 is a sapphire substrate; nucleation layer 2 is an AlGaN layer with a thickness of 30 nm; intrinsic GaN layer 3 has a thickness of 400 nm; and the Si doping concentration in N-type semiconductor layer 4 is 7 × 10⁻⁶. 18 cm -3 Its thickness is 2μm.

[0094] Among them, the multi-quantum well layer 5 consists of alternating stacked InGaN quantum well layers and GaN quantum barrier layers, with a stacking period of 10. The thickness of a single InGaN quantum well layer is 3nm, and the thickness of a single GaN quantum barrier layer is 10nm.

[0095] Among them, electron blocking layer 6 is Al c Ga 1-c N layers (c = 0.12) and In d Ga 1-d A periodic structure with N alternating layers (d = 0.3) and a period number of 8, where a single Al c Ga 1-c The thickness of the N layer is 6nm, and a single In... d Ga 1-d The thickness of the N layer is 6 nm.

[0096] The P-type semiconductor layer 7 comprises a sequentially stacked InN quantum dot layer 72 and a C / O co-doped P-type GaN thin film layer 71. The InN quantum dot layer 72 has an In content of 0.2% and a thickness of 3 nm. The C / O co-doped P-type GaN thin film layer 71 has a C doping concentration of 1 × 10⁻⁶. 18 cm -3 The O doping concentration is 2 × 10⁻⁶. 17 cm -3 The Mg doping concentration is 5 × 10⁻⁶. 19 cm -3 The thickness is 7nm.

[0097] The method for fabricating the GaN-based light-emitting diode epitaxial wafer in this embodiment includes the following steps:

[0098] (1) Provide a substrate; load the substrate into MOCVD and anneal it at 1120℃, 400 torr, and hydrogen atmosphere for 6 min.

[0099] (2) Growing a nucleation layer on a substrate;

[0100] Specifically, the AlGaN layer was grown using MOCVD at a growth temperature of 620℃ and a growth pressure of 250 torr. During growth, NH3 was introduced into the MOCVD reaction chamber as the N source; H2 and N2 were used as carrier gases; TMAl was introduced as the Al source; and TMGa was introduced as the Ga source.

[0101] (3) Grow an intrinsic GaN layer on the nucleation layer;

[0102] Specifically, intrinsic GaN layers were grown using MOCVD at a growth temperature of 1100℃ and a growth pressure of 250 tor. During growth, NH3 was introduced into the MOCVD reaction chamber as the N source, and H2 and N2 were used as carrier gases, while TMGa was introduced as the Ga source.

[0103] (4) Grow an N-type semiconductor layer on the intrinsic GaN layer;

[0104] Specifically, an N-type semiconductor layer was grown using MOCVD at a growth temperature of 1120℃ and a growth pressure of 150 torr. During growth, NH3 was introduced into the MOCVD reaction chamber as an N source and SiH4 was introduced as an N-type doping source. H2 and N2 were used as carrier gases, and TMGa was introduced as a Ga source.

[0105] (5) Growing a multi-quantum-well layer on an N-type semiconductor layer;

[0106] Specifically, quantum well layers and quantum barrier layers are periodically grown in MOCVD to obtain multiple quantum well layers;

[0107] The quantum well layer is grown at a temperature of 750℃ and a growth pressure of 300 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, N2 is introduced as the carrier gas, TEGa is introduced as the Ga source, and TMIn is introduced as the In source. The quantum barrier layer is grown at a temperature of 820℃ and a growth pressure of 300 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, H2 and N2 are introduced as the carrier gases, and TEGa is introduced as the Ga source.

[0108] (6) An electron blocking layer is grown on the composite insertion layer;

[0109] Specifically, Al is periodically grown in MOCVD. cGa 1-c N layers and In d Ga 1-d The N-layer acts as an electron-blocking layer. Al c Ga 1-c The N-layer was grown at a temperature of 950℃ and a growth pressure of 250 torr. During growth, NH3 was introduced into the MOCVD reaction chamber as the N source, N2 and H2 were used as carrier gases, TMAl was introduced as the Al source, and TMGa was introduced as the Ga source. d Ga 1-d The N-layer was grown at a temperature of 950℃ and a growth pressure of 250 torr. During growth, NH3 was introduced into the MOCVD reaction chamber as the N source, N2 and H2 were used as carrier gases, TMIn was introduced as the In source, and TMGa was introduced as the Ga source.

[0110] (7) Grow a P-type semiconductor layer on the electron blocking layer;

[0111] (I) Growth of InN quantum dot layers on electron blocking layers;

[0112] Specifically, InN quantum dot layers were grown in MOCVD at a growth temperature of 750℃ and a growth pressure of 300 torr. NH3 was introduced as the N source and TMIn was introduced as the In source. N2 was used as the carrier gas during growth.

[0113] (II) Growth of a P-type GaN thin film layer on an InN quantum dot layer;

[0114] Specifically, a p-type GaN thin film was grown in MOCVD at a temperature of 900℃ and a pressure of 200 torr. During growth, TEGa was introduced as the Ga source, CP2Mg as the p-type doped Mg source, and NH3 as the N source into the MOCVD reaction chamber. H2 was used as the carrier gas during growth.

[0115] (III) Annealing the P-type GaN thin film layer to obtain a C / O co-doped P-type GaN thin film layer;

[0116] Specifically, the P-type GaN thin film layer was transferred to the reaction chamber of a rapid annealing furnace for annealing. The annealing atmosphere was N2 and CO2, with a flow rate of 15 mL / min for N2 and 20 mL / min for CO2. The annealing temperature was 600℃, the annealing pressure was 300 torr, and the annealing time was 5 min.

[0117] Comparative Example 1

[0118] This comparative example provides a GaN-based light-emitting diode epitaxial wafer, which differs from Example 1 in that the P-type semiconductor layer in the GaN-based light-emitting diode epitaxial wafer is a P-type GaN layer. Accordingly, in the fabrication method, this layer does not undergo an annealing step, while the rest is the same as in Example 1.

[0119] The GaN-based light-emitting diode epitaxial wafers obtained in Examples 1-2 and Comparative Example 1 were tested for brightness, antistatic capability, and surface roughness. The specific test methods are as follows:

[0120] (1) The epitaxial wafer was fabricated into a chip with a vertical structure of 10mil×24mil, and its luminous brightness was tested;

[0121] (2) Antistatic performance test: The antistatic performance of the base chip was tested using an electrostatic meter under the HBM (human body discharge model) model. The percentage of chips that could withstand 6000V reverse static electricity was tested.

[0122] (3) Roughness: Surface roughness was tested using an atomic force microscope (AFM, model NanoScope MultiMode).

[0123] The specific results are as follows:

[0124]

[0125] As can be seen from the table, when the traditional GaN-based LED epitaxial wafer (Comparative Example 1) is replaced with the GaN-based LED epitaxial wafer structure of this invention, the brightness increases from 192.3mW to 194.3mW, the antistatic capability increases from 88.7 to 93.2, and the surface roughness decreases from 0.211nm to 0.195nm. This indicates that by setting a C / O co-doped P-type GaN thin film layer in the GaN-based LED epitaxial wafer, this invention can effectively improve brightness, enhance antistatic capability, and reduce surface roughness.

[0126] The above description is a preferred embodiment of the invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the invention, and these improvements and modifications are also considered to be within the scope of protection of the invention.

Claims

1. A GaN-based light-emitting diode epitaxial wafer, comprising a substrate and a nucleation layer, an intrinsic GaN layer, an N-type semiconductor layer, a multiple quantum well layer, an electron blocking layer, and a P-type semiconductor layer sequentially disposed on the substrate; characterized in that, The P-type semiconductor layer includes an InN quantum dot layer and a C / O co-doped P-type GaN thin film layer; the InN quantum dot layer is disposed between the electron blocking layer and the C / O co-doped P-type GaN thin film layer; the C / O co-doped P-type GaN thin film layer is prepared by annealing the P-type GaN thin film layer in a mixed atmosphere of N2 and CO2.

2. The GaN-based light-emitting diode epitaxial wafer as described in claim 1, characterized in that, The C doping concentration in the C / O co-doped P-type GaN thin film is 5 × 10⁻⁶. 17 cm -3 -5×10 18 cm -3 The doping concentration of O is 1×10⁻⁶. 17 cm -3 -1×10 18 cm -3 .

3. The GaN-based light-emitting diode epitaxial wafer as described in claim 1, characterized in that, The P-type dopant element in the C / O co-doped P-type GaN thin film is Mg, and the Mg doping concentration is 5 × 10⁻⁶. 17 cm -3 -1×10 20 cm -3 The thickness of the C / O co-doped P-type GaN thin film is 5nm-50nm.

4. The GaN-based light-emitting diode epitaxial wafer as described in claim 1, characterized in that, The proportion of In component in the InN quantum dot layer is 0.1-0.5, and the thickness of the InN quantum dot layer is 1nm-5nm.

5. A method for fabricating a GaN-based light-emitting diode epitaxial wafer, used to fabricate the GaN-based light-emitting diode epitaxial wafer as described in any one of claims 1-4, characterized in that, include: A substrate is provided on which a nucleation layer, an intrinsic GaN layer, an N-type semiconductor layer, a multiple quantum well layer, an electron blocking layer, and a P-type semiconductor layer are sequentially grown. The P-type semiconductor layer comprises an InN quantum dot layer and a C / O co-doped P-type GaN thin film layer. The InN quantum dot layer is disposed between the electron blocking layer and the C / O co-doped P-type GaN thin film layer. The C / O co-doped P-type GaN thin film layer is prepared by annealing the P-type GaN thin film layer in a mixed atmosphere of N2 and CO2.

6. The method for fabricating a GaN-based light-emitting diode epitaxial wafer as described in claim 5, characterized in that, The growth method of the C / O co-doped P-type GaN thin film layer is as follows: the P-type GaN thin film layer is grown by MOCVD at a growth temperature of 900℃-1000℃ and a growth pressure of 100 torr-300 torr, with H2 as the carrier gas; the P-type GaN thin film layer is annealed in an atmosphere of N2 and CO2, wherein the flow rate of N2 is 5 mL / min-30 mL / min, the flow rate of CO2 is 10 mL / min-50 mL / min, the annealing temperature is 500℃-800℃, the annealing pressure is 100 torr-500 torr, and the annealing time is 3 min-10 min.

7. The method for fabricating a GaN-based light-emitting diode epitaxial wafer as described in claim 5, characterized in that, The growth temperature of the InN quantum dot layer is 700℃-800℃, the growth pressure is 200 torr-500 torr, and the carrier gas used during growth is N2.

8. A GaN-based light-emitting diode, characterized in that, Including the GaN-based light-emitting diode epitaxial wafer as described in any one of claims 1-4.

Images