A deep ultraviolet light-emitting diode epitaxial wafer and its preparation method, and a light-emitting diode

Abstract

The present invention discloses a deep ultraviolet light-emitting diode epitaxial wafer, a method for preparing the same, and a light-emitting diode, relating to the field of semiconductor optoelectronic devices. The deep ultraviolet light-emitting diode epitaxial wafer comprises a substrate and a buffer layer, an undoped AlGaN layer, an N-type AlGaN layer, a multi-quantum well layer, an electron blocking layer, a P-type AlGaN layer, and a P-type contact layer, sequentially deposited on the substrate. The buffer layer comprises an AlON layer, an AlN layer, and a Ga-doped AlN layer, sequentially deposited on the substrate. Implementation of the present invention can effectively improve the luminous efficiency of deep ultraviolet light-emitting diodes.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor optoelectronic devices, and in particular to a deep ultraviolet light-emitting diode epitaxial wafer and a preparation method thereof, and a light-emitting diode. Background Art

[0002] Currently, deep ultraviolet LEDs primarily use AlGaN as the primary growth material, using metal-organic vapor deposition (MOCVD) epitaxial growth to grow the required epitaxial structure. This epitaxial structure specifically includes an AlN buffer layer, a non-doped AlGaN layer, an n-type AlGaN layer, an AlGaN quantum well layer, a p-type AlGaN electron barrier layer, and a p-type GaN layer. Although deep ultraviolet AlGaN LEDs are currently widely used, two major issues severely limit the improvement of the luminous efficiency of AlGaN deep ultraviolet light-emitting diodes. First, when depositing an AlN layer or an AlGaN epitaxial layer on a foreign substrate, the large lattice mismatch between the AlN layer or AlGaN epitaxial layer and the foreign substrate causes excessive stress in the epitaxial layer, which can cause the AlN layer or AlGaN epitaxial layer to break when grown to a certain thickness. Second, the poor crystal quality of the AlN layer or AlGaN layer results in a high dislocation density in the ultraviolet LED epitaxial layer, which significantly reduces the internal quantum efficiency of the light-emitting diode and seriously reduces the luminous efficiency of the ultraviolet LED. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a deep ultraviolet light-emitting diode epitaxial wafer and a preparation method thereof, which can effectively alleviate the lattice mismatch and thermal mismatch between the substrate and the AlGaN material and improve the luminous efficiency.

[0004] Another technical problem to be solved by the present invention is to provide a light emitting diode with high luminous efficiency.

[0005] In order to solve the above problems, the present invention discloses a deep ultraviolet light-emitting diode epitaxial wafer, comprising a substrate and a buffer layer, an undoped AlGaN layer, an N-type AlGaN layer, a multi-quantum well layer, an electron blocking layer, a P-type AlGaN layer and a P-type contact layer deposited in sequence on the substrate; wherein the buffer layer comprises an AlON layer, an AlN layer and a Ga-doped AlN layer deposited in sequence on the substrate.

[0006] As an improvement of the above technical solution, the proportion of the O component in the AlON layer is 0.01-0.1, and the thickness of the AlON layer is 5-50 nm.

[0007] As an improvement of the above technical solution, the thickness of the AlN layer is 10-100 nm, and the thickness of the Ga-doped AlN layer is 10-100 nm.

[0008] As an improvement of the above technical solution, the proportion of Ga component in the Ga-doped AlN layer is 0.01-0.1.

[0009] As an improvement to the above technical solution, the content of Ga component in the Ga-doped AlN layer is greater than the content of Ga component in the undoped AlGaN layer;

[0010] The content of the Ga component in the Ga-doped AlN layer gradually decreases from the AlN layer side to the content of the Ga component in the non-doped AlGaN layer.

[0011] Correspondingly, the present invention also discloses a method for preparing a deep ultraviolet light-emitting diode epitaxial wafer, which is used to prepare the above-mentioned deep ultraviolet light-emitting diode epitaxial wafer, comprising:

[0012] (1) providing a substrate;

[0013] (2) sequentially growing a buffer layer, an undoped AlGaN layer, an N-type AlGaN layer, a multi-quantum well layer, an electron blocking layer, a P-type AlGaN layer, and a P-type contact layer on the substrate;

[0014] The buffer layer includes an AlON layer, an AlN layer and a Ga-doped AlN layer sequentially arranged on the substrate.

[0015] As an improvement of the above technical solution, in step (2), the AlON layer and the AlN layer are sputtered by PVD, with a sputtering power of 2-5 kW, a sputtering temperature of 300-800° C., and a sputtering pressure of 1-50 torr;

[0016] The sputtering atmosphere of the AlON layer is a mixed gas of N2, Ar and O2, and the volume ratio of N2, Ar and O2 is (1-10): (5-30): 1; the sputtering atmosphere of the AlN layer is a mixed gas of N2 and Ar; wherein, the volume ratio of N2 and Ar is 1: (1-10).

[0017] As an improvement to the above technical solution, in step (2), after the AlON layer and the AlN layer are sputtered, MOCVD is used for treatment, the treatment atmosphere is H2, the treatment temperature is 1000-1300°C, and the pressure is 50-500 torr.

[0018] As an improvement of the above technical solution, in step (2), MOCVD is used to grow the Ga-doped AlN layer, the growth temperature is 800-1200°C, the growth pressure is 50-500 torr, and the growth atmosphere is a mixed gas of N2 and NH3, wherein the volume ratio of N2 to NH3 is (1-10):1.

[0019] Correspondingly, the present invention also discloses a deep ultraviolet light emitting diode, comprising the above-mentioned deep ultraviolet light emitting diode epitaxial wafer.

[0020] The implementation of the present invention has the following beneficial effects:

[0021] The deep ultraviolet light-emitting diode epitaxial wafer of the present invention has a buffer layer deposited between the epitaxial structure and the substrate. Specifically, the buffer layer structure includes an AlON layer, an AlN layer, and a Ga-doped AlN layer. Based on this structure of the buffer layer, firstly, it reduces the lattice mismatch between the substrate and AlGaN, lowers the dislocation density, prevents dislocations from extending into the quantum well, reduces the non-radiative recombination centers generated by dislocations in the quantum well, and improves the luminous efficiency of the quantum well. Secondly, the buffer layer provides nucleation centers with the same orientation as the substrate, relieves the stress generated by the lattice mismatch between the AlGaN and the substrate and the thermal stress generated by the mismatch in thermal expansion coefficients, provides a flat nucleation surface for the subsequent growth of AlGaN, reduces the contact angle of its nucleation growth, and promotes the two-dimensional growth of AlGaN. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 1 is a schematic structural diagram of a deep ultraviolet light-emitting diode epitaxial wafer in one embodiment of the present invention;

[0023] Figure 2 is a schematic structural diagram of a buffer layer in one embodiment of the present invention;

[0024] Figure 3 This is a flow chart of a method for preparing a deep ultraviolet light-emitting diode epitaxial wafer in one embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is described in further detail below.

[0026] refer to Figure 1 and Figure 2 The present invention discloses a deep ultraviolet light-emitting diode epitaxial wafer, comprising a substrate 1 and a buffer layer 2, a non-doped AlGaN layer 3, an N-type AlGaN layer 4, a multi-quantum well layer 5, an electron blocking layer 6, a P-type AlGaN layer 7 and a P-type contact layer 8 sequentially deposited on the substrate 1. The buffer layer comprises an AlON layer 21, an AlN layer 22 and a Ga-doped AlN layer 23 sequentially deposited on the substrate 1. Based on this buffer layer structure, on the one hand, the lattice mismatch between the substrate and AlGaN is reduced, the dislocation density is reduced, the dislocation is prevented from extending to the quantum well, the non-radiative recombination center generated by the dislocation in the quantum well is reduced, and the luminous efficiency of the quantum well is improved. Secondly, the buffer layer provides a nucleation center with the same orientation as the substrate, releases the stress generated by the lattice mismatch between AlGaN and the substrate and the thermal stress generated by the mismatch of thermal expansion coefficients, provides a flat nucleation surface for the subsequent growth of AlGaN, reduces the contact angle of its nucleation growth, and promotes the two-dimensional growth of AlGaN.

[0027] Among them, the AlON layer 21 is arranged close to the substrate 1, which can alleviate the lattice mismatch between the substrate 1 and the AlN layer 22. It should be noted that since the substrate 1 is generally sapphire (Al2O3), the O component is introduced into this layer. The O component can play a role in reducing the lattice mismatch between Al2O3 and AlN. Specifically, the proportion of the O component is 0.01-0.1. When its proportion is less than 0.01, it is difficult to effectively alleviate the lattice mismatch; when its proportion is greater than 0.1, it will reduce the quality of the AlON crystal, and the setting affects the quality of the AlN crystal in the AlN layer 22. Exemplarily, the proportion of the O component is 0.02, 0.03, 0.04, 0.05, 0.06 or 0.08, but is not limited to this.

[0028] It should be noted that, from the perspective of reducing lattice mismatch, the higher the O component content in AlON, the more beneficial it is, but too high an O component will produce more amorphous phases, thereby affecting the crystal quality of the AlON layer 21 and the AlN layer 22. To this end, the present invention performs heat treatment on the AlON layer 21 and the AlN layer 22 after depositing them. Through this heat treatment, the recrystallization of the AlON layer 21 and the AlN layer 22 can be promoted, and their crystal quality can be improved. After introducing this heat treatment process, the O component in the AlON layer 21 can be increased to 0.03-0.1. Further preferably, during the heat treatment process, an H2 atmosphere is adopted, and the heat treatment temperature is controlled to 1000-1300°C. Based on the above control, the O component in the AlON layer 21 can be increased to 0.7-0.1.

[0029] The thickness of the AlON layer 21 is 5-50 nm. When its thickness is less than 5 nm, it is difficult to alleviate the lattice mismatch between the substrate 1 and the AlN layer 22. When its thickness is greater than 50 nm, the thermal expansion difference between the buffer layer 2 as a whole and the AlGaN material is large, making it difficult to effectively alleviate thermal stress. Exemplarily, the thickness of the AlON layer 21 is 17 nm, 24 nm, 31 nm, 38 nm, 45 nm, or 47 nm, but is not limited thereto.

[0030] The thickness of the AlN layer 22 is 10-100 nm. When the thickness is less than 10 nm, dislocations cannot be effectively blocked. When the thickness is greater than 100 nm, the overall crystal quality of the AlN layer is poor, reducing the internal quantum efficiency of the light-emitting diode. Exemplary thicknesses of the AlN layer 22 are 15 nm, 20 nm, 25 nm, 30 nm, 40 nm, 50 nm, 70 nm, 85 nm, or 90 nm, but are not limited thereto.

[0031] Among them, the Ga-doped AlN layer 23 can reduce the lattice mismatch between the AlN layer 22 and the undoped AlGaN layer 3. Specifically, the proportion of Ga component in the Ga-doped AlN layer 23 is 0.01-0.1, and exemplarily is 0.02, 0.03, 0.04, 0.05, 0.06 or 0.08, but is not limited thereto. Preferably, in one embodiment of the present invention, the content of Ga component in the Ga-doped AlN layer 23 is greater than the content of Ga component in the undoped AlGaN layer 3, and the content of Ga component in the Ga-doped AlN layer 23 gradually decreases from the AlN layer 22 side to the content of Ga component in the undoped AlGaN layer 3. Based on the above-mentioned component changes, the lattice mismatch between the AlN layer 22 and the undoped AlGaN layer 3 can be better reduced.

[0032] Specifically, the thickness of the Ga-doped AlN layer 23 is 10-100 nm, and illustratively, is 15 nm, 20 nm, 25 nm, 30 nm, 40 nm, 50 nm, 70 nm, 85 nm, or 90 nm, but is not limited thereto.

[0033] The substrate 1 may be a sapphire substrate, a silicon substrate, or a silicon carbide substrate, but is not limited thereto, and is preferably a sapphire substrate.

[0034] The undoped AlGaN layer 3 can form a central island growth, providing a good foundation for the subsequent layers to transition to two-dimensional growth. It can also release compressive stress and improve crystal quality. Specifically, the thickness of the undoped AlGaN layer 3 is 1-5μm, and exemplary thicknesses include 1.4μm, 1.8μm, 2.2μm, 2.6μm, 3μm, 3.5μm, 4μm, 4.2μm, or 4.6μm, but is not limited thereto.

[0035] The N-type AlGaN layer 4 can provide electrons, which then recombine with holes in the multi-quantum well layer 5 to emit light. Specifically, the doping element in the N-type AlGaN layer 4 is Si, but not limited thereto. The doping concentration of Si in the N-type AlGaN layer 4 is 1×10 19 -5×10 20 cm -3 , an exemplary value is 3.5×10 19 cm -3 , 8×10 19 cm -3 , 1.2×10 20 cm -3 , 2.4×10 20 cm -3 , 3.5×10 20 cm -3 or 4.3 × 10 20 cm -3Specifically, the thickness of the N-type AlGaN layer 4 is 1-5 μm, and exemplarily is 1.4 μm, 1.8 μm, 2.2 μm, 2.6 μm, 3 μm, 3.5 μm, 4 μm, 4.2 μm or 4.6 μm, but not limited thereto.

[0036] Among them, the multi-quantum well layer 5 is an alternately stacked Al x Ga 1-x N quantum well layer and Al y Ga 1-y N quantum barrier layers, stacking period number 6-12. Single Al x Ga 1-x The thickness of the N quantum well layer is 2-5nm, and x is 0.2-0.6. y Ga 1-y The thickness of the N quantum barrier layer is 5-15 nm, and y is 0.4-0.8.

[0037] The electron blocking layer 6 can effectively limit the electron overflow, reduce the blocking of holes, improve the injection efficiency of holes into the quantum well, reduce the carrier Auger recombination, and improve the luminous efficiency of the light-emitting diode. a Ga 1-a N layer, but not limited thereto. Specifically, the thickness of the electron blocking layer 6 is 10-50nm, Al a Ga 1-a In the N layer, a is 0.4-0.8.

[0038] The doping element of the P-type AlGaN layer 7 is Mg, but not limited thereto. The doping concentration of Mg in the P-type AlGaN layer 7 is 1×10 19 -5×10 20 cm -3 , the thickness of the P-type AlGaN layer 7 is 100-200 nm.

[0039] The P-type contact layer 8 is a high-doping AlGaN layer. Specifically, the Mg doping concentration in the P-type contact layer 8 is 5×10 19 -5×10 20 cm -3 , the thickness of the P-type contact layer 8 is 10-50nm.

[0040] Accordingly, reference Figure 3 The present invention also discloses a method for preparing a deep ultraviolet light-emitting diode epitaxial wafer, which is used to prepare the above-mentioned deep ultraviolet light-emitting diode epitaxial wafer, and comprises the following steps:

[0041] S1: providing a substrate;

[0042] Specifically, the substrate is a sapphire substrate, a silicon substrate, or a silicon carbide substrate, but is not limited thereto. Preferably, the substrate is a sapphire substrate, which is widely used, low in cost, easy to clean, and has good stability at high temperatures.

[0043] S2: sequentially growing a buffer layer, an undoped AlGaN layer, an N-type AlGaN layer, a multi-quantum well layer, an electron blocking layer, a P-type AlGaN layer, and a P-type contact layer on the substrate;

[0044] Specifically, S2 includes:

[0045] S21: growing a buffer layer on the substrate;

[0046] Specifically, S21 includes:

[0047] S211: growing an AlON layer on the substrate;

[0048] The AlON layer can be grown by PVD or MOCVD, but is not limited thereto. Preferably, in one embodiment of the present invention, the AlON layer is sputtered in PVD. The AlON layer prepared by PVD magnetron sputtering technology has high crystal quality, high surface uniformity, and strong uniaxial orientation.

[0049] Specifically, when PVD magnetron sputtering is used to sputter the AlON layer, the sputtering power is 2-5 kW, the sputtering temperature is 300-800° C., and the sputtering pressure is 1-50 torr.

[0050] Furthermore, the sputtering atmosphere is controlled to be a mixture of N2, Ar, and O2. Specifically, the volume ratio of N2, Ar, and O2 is (1-10):(5-30):1, with examples being 1:6:1, 2:8:1, 3:15:1, 5:18:1, and 7:22:1, but not limited thereto. Controlling the sputtering atmosphere further reduces the internal stress accumulated during AlON layer growth.

[0051] S212: growing an AlN layer on the AlON layer;

[0052] The AlN layer can be grown by PVD or MOCVD, but is not limited thereto. Preferably, in one embodiment of the present invention, the AlN layer is sputtered by PVD. The AlN layer prepared by PVD magnetron sputtering technology has high crystal quality, high surface uniformity, and strong uniaxial orientation.

[0053] Specifically, when PVD magnetron sputtering is used to sputter the AlON layer, the sputtering power is 2-5 kW, the sputtering temperature is 300-800° C., and the sputtering pressure is 1-50 torr.

[0054] Furthermore, the sputtering atmosphere is controlled to be a mixture of N₂ and Ar. Specifically, the volume ratio of N₂ to Ar is 1:(1-10), with exemplary ratios of 1:1.5, 1:3, 1:5, 1:7, or 1:8 being examples, but not limited to these. Controlling the sputtering atmosphere improves the crystal quality of the AlN layer and reduces the internal stress accumulated during AlN layer growth.

[0055] S213: subjecting the substrate obtained in step S212 to high temperature treatment;

[0056] Specifically, after the AlON and AlN layers are sputtered, the substrate is loaded into the MOCVD and heat treated. Through heat treatment, the amorphous phase in the AlON and AlN layers can be crystallized to improve the crystal quality. The high-temperature treatment pressure is 50-500 torr and the temperature is 1000-1300°C. When the high-temperature treatment temperature is less than 1000°C, the excess O component is difficult to be effectively removed; when the high-temperature treatment temperature is greater than 1300°C, the crystal structure of the AlON and AlN layers will be destroyed.

[0057] S214: growing a Ga-doped AlN layer on the AlN layer;

[0058] The Ga-doped AlN layer is grown using MOCVD at a growth temperature of 800-1200°C, a growth pressure of 50-500 torr, and a growth atmosphere of a mixture of N2 and NH3. This atmosphere control can reduce side reactions between Al and H2, improving the crystal quality of the Ga-doped AlN layer. Specifically, the volume ratio of N2 to NH3 is (1-10):1, with exemplary ratios of 2:1, 3.5:1, 5:1, 7.5:1, or 9:1 being examples, but not limited to these.

[0059] S22: growing a non-doped AlGaN layer on the Ga-doped AlN layer;

[0060] The non-doped AlGaN layer is grown by MOCVD at a growth temperature of 1000-1300° C. and a growth pressure of 50-500 Torr.

[0061] S23: forming an N-type AlGaN layer on the non-doped AlGaN layer;

[0062] The N-type AlGaN layer is grown using MOCVD at a growth temperature of 1000-1300° C. and a growth pressure of 80-200 Torr.

[0063] S24: growing a multi-quantum well layer on the N-type AlGaN layer;

[0064] Among them, MOCVD is used to periodically grow multiple Al x Ga 1-x N quantum well layer and Aly Ga 1-y N quantum barrier layers, that is, a multi-quantum well layer is obtained. Among them, Al x Ga 1-x The growth temperature of the N quantum well layer is 850-950℃ and the growth pressure is 50-300torr. y Ga 1-y The growth temperature of the N quantum barrier layer is 1050-1150° C., and the growth pressure is 50-300 torr.

[0065] S25: growing an electron blocking layer on the multi-quantum well layer;

[0066] The electron blocking layer is grown by MOCVD at a growth temperature of 1000-1100° C. and a growth pressure of 100-300 Torr.

[0067] S26: growing a P-type AlGaN layer on the electron blocking layer;

[0068] The P-type AlGaN layer is grown using MOCVD, with a growth temperature of 1000-1100°C and a growth pressure of 100-600 Torr.

[0069] S27: growing a P-type contact layer on the P-type AlGaN layer;

[0070] The P-type contact layer is grown by MOCVD at a growth temperature of 1000-1100° C. and a growth pressure of 100-600 Torr.

[0071] The present invention will be further described below with specific embodiments:

[0072] Example 1

[0073] This embodiment provides a deep ultraviolet light emitting diode epitaxial wafer, referring to Figure 1 、 Figure 2 It includes a substrate 1 and a buffer layer 2, an undoped AlGaN layer 3, an N-type AlGaN layer 4, a multi-quantum well layer 5, an electron blocking layer 6, a P-type AlGaN layer 7 and a P-type contact layer 8 deposited in sequence on the substrate 1.

[0074] Wherein, the substrate 1 is a sapphire substrate.

[0075] The buffer layer 2 includes an AlON layer 21, an AlN layer 22, and a Ga-doped AlN layer 23, which are sequentially deposited on the substrate 1. The O component in the AlON layer 21 is 0.03, and the thickness of the AlON layer 21 is 20 nm. The thickness of the AlN layer is 30 nm. The Ga component in the Ga-doped AlN layer 23 gradually decreases from 0.9 to 0.2 (from the AlN layer 22 side to the undoped AlGaN layer 3 side), and the thickness of the Ga-doped AlN layer 23 is 50 nm.

[0076] The thickness of the non-doped AlGaN layer 3 is 2.5 μm, the thickness of the N-type AlGaN layer 4 is 2.8 μm, and the Si doping concentration is 2.5×10 19 cm -3 .

[0077] Among them, the multi-quantum well layer is an alternately stacked Al x Ga 1-x N quantum well layer (x = 0.45) and Al y Ga 1-y N quantum barrier layer (y=0.55), the number of stacking periods is 9. Single Al x Ga 1-x The thickness of the N quantum well layer is 3.5nm, and the single Al y Ga 1-y The thickness of the N quantum barrier layer is 11 nm.

[0078] The electron blocking layer 6 is Al a Ga 1-a The thickness of the N layer (a=0.65) is 30 nm. The thickness of the P-type AlGaN layer 7 is 150 nm, and the Mg doping concentration is 5×10 19 cm -3 The P-type contact layer 8 is a P-type doped AlGaN layer with a Mg doping concentration of 1×10 20 cm -3 , with a thickness of 20nm.

[0079] The preparation method of the deep ultraviolet light-emitting diode epitaxial wafer in this embodiment is as follows:

[0080] (1) providing a substrate;

[0081] (2) growing an AlON layer on a substrate;

[0082] Specifically, the AlON layer was sputtered in PVD with a sputtering power of 3.5 kW, a sputtering temperature of 600° C., a sputtering pressure of 15 torr, and a sputtering atmosphere of a mixed gas of N 2 , Ar, and O 2 (the volume ratio of the three being 6:18:1).

[0083] (3) growing an AlN layer on the AlON layer;

[0084] Specifically, the AlN layer was sputtered in PVD with a sputtering power of 3.5 kW, a sputtering temperature of 600° C., a sputtering pressure of 15 torr, and a sputtering atmosphere of a mixed gas of N 2 and Ar (the volume ratio of the two being 1:6).

[0085] (4) growing a Ga-doped AlN layer on the AlN layer;

[0086] Specifically, the Ga-doped AlN layer was grown by MOCVD at a growth temperature of 1000° C., a growth pressure of 100 torr, and a growth atmosphere of a mixed gas of N 2 and NH 3 (the volume ratio of the two being 3:1).

[0087] (5) growing a non-doped AlGaN layer on the Ga-doped AlN layer;

[0088] Specifically, the non-doped AlGaN layer is grown by MOCVD at a growth temperature of 1200° C. and a growth pressure of 100 Torr.

[0089] (6) an N-type AlGaN layer on the non-doped AlGaN layer;

[0090] Specifically, MOCVD is used to grow the N-type AlGaN layer at a growth temperature of 1200° C. and a growth pressure of 100 Torr.

[0091] (7) growing a multi-quantum well layer on the N-type AlGaN layer;

[0092] Specifically, MOCVD is used to periodically grow multiple Al x Ga 1-x N quantum well layer and Al y Ga 1-y N quantum barrier layer. Among them, Al x Ga 1-x The growth temperature of the N quantum well layer is 900℃ and the growth pressure is 200torr. y Ga 1-y The growth temperature of the N quantum barrier layer is 1100°C and the growth pressure is 200 torr.

[0093] (8) growing an electron blocking layer on the multi-quantum well layer;

[0094] Specifically, the electron blocking layer is grown by MOCVD at a growth temperature of 1050° C. and a growth pressure of 200 Torr.

[0095] (9) growing a P-type AlGaN layer on the electron blocking layer;

[0096] Specifically, the P-type AlGaN layer is grown by MOCVD at a growth temperature of 1050° C. and a growth pressure of 300 Torr.

[0097] (10) growing a P-type contact layer on the P-type AlGaN layer;

[0098] Specifically, the P-type contact layer is grown by MOCVD at a growth temperature of 1040° C. and a growth pressure of 250 Torr.

[0099] Example 2

[0100] This embodiment provides a deep ultraviolet light emitting diode epitaxial wafer, referring to Figure 1 、 Figure 2 It includes a substrate 1 and a buffer layer 2, an undoped AlGaN layer 3, an N-type AlGaN layer 4, a multi-quantum well layer 5, an electron blocking layer 6, a P-type AlGaN layer 7 and a P-type contact layer 8 deposited in sequence on the substrate 1.

[0101] Wherein, the substrate 1 is a sapphire substrate.

[0102] The buffer layer 2 includes an AlON layer 21, an AlN layer 22, and a Ga-doped AlN layer 23, which are sequentially deposited on the substrate 1. The O component in the AlON layer 21 is 0.03, and the thickness of the AlON layer 21 is 20 nm. The thickness of the AlN layer is 30 nm. The Ga component in the Ga-doped AlN layer 23 gradually decreases from 0.9 to 0.2 (from the AlN layer 22 side to the undoped AlGaN layer 3 side), and the thickness of the Ga-doped AlN layer 23 is 50 nm.

[0103] The thickness of the non-doped AlGaN layer 3 is 2.5 μm, the thickness of the N-type AlGaN layer 4 is 2.8 μm, and the Si doping concentration is 2.5×10 19 cm -3 .

[0104] Among them, the multi-quantum well layer is an alternately stacked Al x Ga 1-x N quantum well layer (x = 0.45) and Al y Ga 1-y N quantum barrier layer (y=0.55), the number of stacking periods is 9. Single Al x Ga 1-x The thickness of the N quantum well layer is 3.5nm, and the single Al y Ga 1-y The thickness of the N quantum barrier layer is 11 nm.

[0105] The electron blocking layer 6 is Al a Ga 1-a The thickness of the N layer (a=0.65) is 30 nm. The thickness of the P-type AlGaN layer 7 is 150 nm, and the Mg doping concentration is 5×10 19 cm -3The P-type contact layer 8 is a P-type doped AlGaN layer with a Mg doping concentration of 1×10 20 cm -3 , with a thickness of 20nm.

[0106] The preparation method of the deep ultraviolet light-emitting diode epitaxial wafer in this embodiment is as follows:

[0107] (1) providing a substrate;

[0108] (2) growing an AlON layer on a substrate;

[0109] Specifically, the AlON layer was sputtered in PVD with a sputtering power of 3.5 kW, a sputtering temperature of 600° C., a sputtering pressure of 15 torr, and a sputtering atmosphere of a mixed gas of N 2 , Ar, and O 2 (the volume ratio of the three being 6:18:1).

[0110] (3) growing an AlN layer on the AlON layer;

[0111] Specifically, the AlN layer was sputtered in PVD with a sputtering power of 3.5 kW, a sputtering temperature of 600° C., a sputtering pressure of 15 torr, and a sputtering atmosphere of a mixed gas of N 2 and Ar (the volume ratio of the two being 1:6).

[0112] (4) subjecting the substrate to high temperature treatment;

[0113] Specifically, the heat treatment is performed in MOCVD at a temperature of 1100° C., in an H 2 atmosphere, and at a pressure of 100 torr.

[0114] (5) growing a Ga-doped AlN layer on the AlN layer;

[0115] Specifically, the Ga-doped AlN layer is grown by MOCVD at a growth temperature of 1000° C., a growth pressure of 100 torr, and a growth atmosphere of a mixed gas of N 2 and NH 3 (the volume ratio of the two is 3:1).

[0116] (6) growing a non-doped AlGaN layer on the Ga-doped AlN layer;

[0117] Specifically, the non-doped AlGaN layer is grown by MOCVD at a growth temperature of 1200° C. and a growth pressure of 100 Torr.

[0118] (7) an N-type AlGaN layer on the non-doped AlGaN layer;

[0119] Specifically, MOCVD is used to grow the N-type AlGaN layer at a growth temperature of 1200° C. and a growth pressure of 100 Torr.

[0120] (8) growing a multi-quantum well layer on the N-type AlGaN layer;

[0121] Specifically, MOCVD is used to periodically grow multiple Al x Ga 1-x N quantum well layer and Al y Ga 1-y N quantum barrier layer. Among them, Al x Ga 1-x The growth temperature of the N quantum well layer is 900℃ and the growth pressure is 200torr. y Ga 1-y The growth temperature of the N quantum barrier layer is 1100°C and the growth pressure is 200 torr.

[0122] (9) growing an electron blocking layer on the multi-quantum well layer;

[0123] Specifically, the electron blocking layer is grown by MOCVD at a growth temperature of 1050° C. and a growth pressure of 200 Torr.

[0124] (10) growing a P-type AlGaN layer on the electron blocking layer;

[0125] Specifically, the P-type AlGaN layer is grown by MOCVD at a growth temperature of 1050° C. and a growth pressure of 300 Torr.

[0126] (11) growing a P-type contact layer on the P-type AlGaN layer;

[0127] Specifically, the P-type contact layer is grown by MOCVD at a growth temperature of 1040° C. and a growth pressure of 250 Torr.

[0128] Example 3

[0129] This embodiment provides a deep ultraviolet light emitting diode epitaxial wafer, referring to Figure 1 、 Figure 2 It includes a substrate 1 and a buffer layer 2, an undoped AlGaN layer 3, an N-type AlGaN layer 4, a multi-quantum well layer 5, an electron blocking layer 6, a P-type AlGaN layer 7 and a P-type contact layer 8 deposited in sequence on the substrate 1.

[0130] Wherein, the substrate 1 is a sapphire substrate.

[0131] The buffer layer 2 includes an AlON layer 21, an AlN layer 22, and a Ga-doped AlN layer 23 sequentially deposited on the substrate 1. The O component in the AlON layer 21 is 0.09, and the thickness of the AlON layer 21 is 20 nm. The thickness of the AlN layer is 30 nm. The Ga component in the Ga-doped AlN layer 23 gradually decreases from 0.9 to 0.2 (from the AlN layer 22 side to the undoped AlGaN layer 3 side), and the thickness of the Ga-doped AlN layer 23 is 50 nm.

[0132] The thickness of the non-doped AlGaN layer 3 is 2.5 μm, the thickness of the N-type AlGaN layer 4 is 2.8 μm, and the Si doping concentration is 2.5×10 19 cm -3 .

[0133] Among them, the multi-quantum well layer is an alternately stacked Al x Ga 1-x N quantum well layer (x = 0.45) and Al y Ga 1-y N quantum barrier layer (y=0.55), the number of stacking periods is 9. Single Al x Ga 1-x The thickness of the N quantum well layer is 3.5nm, and the single Al y Ga 1-y The thickness of the N quantum barrier layer is 11 nm.

[0134] The electron blocking layer 6 is Al a Ga 1-a The thickness of the N layer (a=0.65) is 30 nm. The thickness of the P-type AlGaN layer 7 is 150 nm, and the Mg doping concentration is 5×10 19 cm -3 The P-type contact layer 8 is a P-type doped AlGaN layer with a Mg doping concentration of 1×10 20 cm -3 , with a thickness of 20nm.

[0135] The preparation method of the deep ultraviolet light-emitting diode epitaxial wafer in this embodiment is as follows:

[0136] (1) providing a substrate;

[0137] (2) growing an AlON layer on a substrate;

[0138] Specifically, the AlON layer was sputtered in PVD with a sputtering power of 3.5 kW, a sputtering temperature of 600° C., a sputtering pressure of 15 torr, and a sputtering atmosphere of a mixed gas of N 2 , Ar, and O 2 (the volume ratio of the three being 6:18:1).

[0139] (3) growing an AlN layer on the AlON layer;

[0140] Specifically, the AlN layer was sputtered in PVD with a sputtering power of 3.5 kW, a sputtering temperature of 600° C., a sputtering pressure of 15 torr, and a sputtering atmosphere of a mixed gas of N 2 and Ar (the volume ratio of the two being 1:6).

[0141] (4) subjecting the substrate to high temperature treatment;

[0142] Specifically, the heat treatment is performed in MOCVD at a temperature of 1100° C., in an H 2 atmosphere, and at a pressure of 100 torr.

[0143] (5) growing a Ga-doped AlN layer on the AlN layer;

[0144] Specifically, the Ga-doped AlN layer is grown by MOCVD at a growth temperature of 1000° C., a growth pressure of 100 torr, and a growth atmosphere of a mixed gas of N 2 and NH 3 (the volume ratio of the two is 3:1).

[0145] (6) growing a non-doped AlGaN layer on the Ga-doped AlN layer;

[0146] Specifically, the non-doped AlGaN layer is grown by MOCVD at a growth temperature of 1200° C. and a growth pressure of 100 Torr.

[0147] (7) an N-type AlGaN layer on the non-doped AlGaN layer;

[0148] Specifically, MOCVD is used to grow the N-type AlGaN layer at a growth temperature of 1200° C. and a growth pressure of 100 Torr.

[0149] (8) growing a multi-quantum well layer on the N-type AlGaN layer;

[0150] Specifically, MOCVD is used to periodically grow multiple Al x Ga 1-x N quantum well layer and Al y Ga 1-y N quantum barrier layer. Among them, Al x Ga 1-x The growth temperature of the N quantum well layer is 900℃ and the growth pressure is 200torr. y Ga 1-y The growth temperature of the N quantum barrier layer is 1100°C and the growth pressure is 200 torr.

[0151] (9) growing an electron blocking layer on the multi-quantum well layer;

[0152] Specifically, the electron blocking layer is grown by MOCVD at a growth temperature of 1050° C. and a growth pressure of 200 Torr.

[0153] (10) growing a P-type AlGaN layer on the electron blocking layer;

[0154] Specifically, the P-type AlGaN layer is grown by MOCVD at a growth temperature of 1050° C. and a growth pressure of 300 Torr.

[0155] (11) growing a P-type contact layer on the P-type AlGaN layer;

[0156] Specifically, the P-type contact layer is grown by MOCVD at a growth temperature of 1040° C. and a growth pressure of 250 Torr.

[0157] Example 4

[0158] This embodiment provides a deep ultraviolet light emitting diode epitaxial wafer, referring to Figure 1 、 Figure 2 It includes a substrate 1 and a buffer layer 2, an undoped AlGaN layer 3, an N-type AlGaN layer 4, a multi-quantum well layer 5, an electron blocking layer 6, a P-type AlGaN layer 7 and a P-type contact layer 8 deposited in sequence on the substrate 1.

[0159] Wherein, the substrate 1 is a sapphire substrate.

[0160] The buffer layer 2 includes an AlON layer 21, an AlN layer 22, and a Ga-doped AlN layer 23 sequentially deposited on the substrate 1. The O component in the AlON layer 21 is 0.09, and the thickness of the AlON layer 21 is 20 nm. The thickness of the AlN layer is 30 nm. The Ga component in the Ga-doped AlN layer 23 gradually decreases from 0.9 to 0.2 (from the AlN layer 22 side to the undoped AlGaN layer 3 side), and the thickness of the Ga-doped AlN layer 23 is 50 nm.

[0161] The thickness of the non-doped AlGaN layer 3 is 2.5 μm, the thickness of the N-type AlGaN layer 4 is 2.8 μm, and the Si doping concentration is 2.5×10 19 cm -3 .

[0162] Among them, the multi-quantum well layer is an alternately stacked Al x Ga 1-x N quantum well layer (x = 0.45) and Al y Ga 1-y N quantum barrier layer (y=0.55), the number of stacking periods is 9. Single Al x Ga 1-x The thickness of the N quantum well layer is 3.5nm, and the single Al y Ga 1-y The thickness of the N quantum barrier layer is 11 nm.

[0163] The electron blocking layer 6 is Al a Ga 1-a The thickness of the N layer (a=0.65) is 30 nm. The thickness of the P-type AlGaN layer 7 is 150 nm, and the Mg doping concentration is 5×10 19 cm -3 The P-type contact layer 8 is a P-type doped AlGaN layer with a Mg doping concentration of 1×10 20cm -3 , with a thickness of 20nm.

[0164] The preparation method of the deep ultraviolet light-emitting diode epitaxial wafer in this embodiment is as follows:

[0165] (1) providing a substrate;

[0166] (2) growing an AlON layer on a substrate;

[0167] Specifically, the AlON layer was sputtered in PVD with a sputtering power of 3.5 kW, a sputtering temperature of 600° C., a sputtering pressure of 15 torr, and a sputtering atmosphere of a mixed gas of N 2 , Ar, and O 2 (the volume ratio of the three being 6:18:1).

[0168] (3) growing an AlN layer on the AlON layer;

[0169] Specifically, the AlN layer was sputtered in PVD with a sputtering power of 3.5 kW, a sputtering temperature of 600° C., a sputtering pressure of 15 torr, and a sputtering atmosphere of a mixed gas of N 2 and Ar (the volume ratio of the two being 1:6).

[0170] (4) subjecting the substrate to high temperature treatment;

[0171] Specifically, the heat treatment is performed in MOCVD at a temperature of 1100° C., in an N 2 atmosphere, and at a pressure of 100 torr.

[0172] (5) growing a Ga-doped AlN layer on the AlN layer;

[0173] Specifically, the Ga-doped AlN layer was grown by MOCVD at a growth temperature of 1000° C., a growth pressure of 100 torr, and a growth atmosphere of a mixed gas of N 2 and NH 3 (the volume ratio of the two being 3:1).

[0174] (6) growing a non-doped AlGaN layer on the Ga-doped AlN layer;

[0175] Specifically, the non-doped AlGaN layer is grown by MOCVD at a growth temperature of 1200° C. and a growth pressure of 100 Torr.

[0176] (7) an N-type AlGaN layer on the non-doped AlGaN layer;

[0177] Specifically, MOCVD is used to grow the N-type AlGaN layer at a growth temperature of 1200° C. and a growth pressure of 100 Torr.

[0178] (8) growing a multi-quantum well layer on the N-type AlGaN layer;

[0179] Specifically, MOCVD is used to periodically grow multiple Alx Ga 1-x N quantum well layer and Al y Ga 1-y N quantum barrier layer. Among them, Al x Ga 1-x The growth temperature of the N quantum well layer is 900℃ and the growth pressure is 200torr. y Ga 1-y The growth temperature of the N quantum barrier layer is 1100°C and the growth pressure is 200 torr.

[0180] (9) growing an electron blocking layer on the multi-quantum well layer;

[0181] Specifically, the electron blocking layer is grown by MOCVD at a growth temperature of 1050° C. and a growth pressure of 200 Torr.

[0182] (10) growing a P-type AlGaN layer on the electron blocking layer;

[0183] Specifically, the P-type AlGaN layer is grown by MOCVD at a growth temperature of 1050° C. and a growth pressure of 300 Torr.

[0184] (11) growing a P-type contact layer on the P-type AlGaN layer;

[0185] Specifically, the P-type contact layer is grown by MOCVD at a growth temperature of 1040° C. and a growth pressure of 250 Torr.

[0186] Example 5

[0187] This embodiment provides a deep ultraviolet light emitting diode epitaxial wafer, referring to Figure 1 、 Figure 2 It includes a substrate 1 and a buffer layer 2, an undoped AlGaN layer 3, an N-type AlGaN layer 4, a multi-quantum well layer 5, an electron blocking layer 6, a P-type AlGaN layer 7 and a P-type contact layer 8 deposited in sequence on the substrate 1.

[0188] Wherein, the substrate 1 is a sapphire substrate.

[0189] The buffer layer 2 includes an AlON layer 21, an AlN layer 22, and a Ga-doped AlN layer 23 sequentially deposited on the substrate 1. The O component in the AlON layer 21 is 0.09, and the thickness of the AlON layer 21 is 20 nm. The thickness of the AlN layer is 30 nm. The Ga component in the Ga-doped AlN layer 23 gradually decreases from 0.9 to 0.2 (from the AlN layer 22 side to the undoped AlGaN layer 3 side), and the thickness of the Ga-doped AlN layer 23 is 50 nm.

[0190] The thickness of the non-doped AlGaN layer 3 is 2.5 μm, the thickness of the N-type AlGaN layer 4 is 2.8 μm, and the Si doping concentration is 2.5×10 19 cm -3 .

[0191] Among them, the multi-quantum well layer is an alternately stacked Al x Ga 1-x N quantum well layer (x = 0.45) and Al y Ga 1-y N quantum barrier layer (y=0.55), the number of stacking periods is 9. Single Al x Ga 1-x The thickness of the N quantum well layer is 3.5nm, and the single Al y Ga 1-y The thickness of the N quantum barrier layer is 11 nm.

[0192] The electron blocking layer 6 is Al a Ga 1-a The thickness of the N layer (a=0.65) is 30 nm. The thickness of the P-type AlGaN layer 7 is 150 nm, and the Mg doping concentration is 5×10 19 cm -3 The P-type contact layer 8 is a P-type doped AlGaN layer with a Mg doping concentration of 1×10 20 cm -3 , with a thickness of 20nm.

[0193] The preparation method of the deep ultraviolet light-emitting diode epitaxial wafer in this embodiment is as follows:

[0194] (1) providing a substrate;

[0195] (2) growing an AlON layer on a substrate;

[0196] Specifically, the AlON layer was sputtered in PVD with a sputtering power of 3.5 kW, a sputtering temperature of 600° C., a sputtering pressure of 15 torr, and a sputtering atmosphere of a mixed gas of N 2 , Ar, and O 2 (the volume ratio of the three being 6:18:1).

[0197] (3) growing an AlN layer on the AlON layer;

[0198] Specifically, the AlN layer was sputtered in PVD with a sputtering power of 3.5 kW, a sputtering temperature of 600° C., a sputtering pressure of 15 torr, and a sputtering atmosphere of a mixed gas of N 2 and Ar (the volume ratio of the two being 1:6).

[0199] (4) subjecting the substrate to high temperature treatment;

[0200] Specifically, the heat treatment is performed in MOCVD at a temperature of 900° C., an H 2 atmosphere, and a pressure of 100 torr.

[0201] (5) growing a Ga-doped AlN layer on the AlN layer;

[0202] Specifically, the Ga-doped AlN layer was grown by MOCVD at a growth temperature of 1000° C., a growth pressure of 100 torr, and a growth atmosphere of a mixed gas of N 2 and NH 3 (the volume ratio of the two being 3:1).

[0203] (6) growing a non-doped AlGaN layer on the Ga-doped AlN layer;

[0204] Specifically, the non-doped AlGaN layer is grown by MOCVD at a growth temperature of 1200° C. and a growth pressure of 100 Torr.

[0205] (7) an N-type AlGaN layer on the non-doped AlGaN layer;

[0206] Specifically, MOCVD is used to grow the N-type AlGaN layer at a growth temperature of 1200° C. and a growth pressure of 100 Torr.

[0207] (8) growing a multi-quantum well layer on the N-type AlGaN layer;

[0208] Specifically, MOCVD is used to periodically grow multiple Al x Ga 1-x N quantum well layer and Al y Ga 1-y N quantum barrier layer. Among them, Al x Ga 1-x The growth temperature of the N quantum well layer is 900℃ and the growth pressure is 200torr. y Ga 1-y The growth temperature of the N quantum barrier layer is 1100°C and the growth pressure is 200 torr.

[0209] (9) growing an electron blocking layer on the multi-quantum well layer;

[0210] Specifically, the electron blocking layer is grown by MOCVD at a growth temperature of 1050° C. and a growth pressure of 200 Torr.

[0211] (10) growing a P-type AlGaN layer on the electron blocking layer;

[0212] Specifically, the P-type AlGaN layer is grown by MOCVD at a growth temperature of 1050° C. and a growth pressure of 300 Torr.

[0213] (11) growing a P-type contact layer on the P-type AlGaN layer;

[0214] Specifically, the P-type contact layer is grown by MOCVD at a growth temperature of 1040° C. and a growth pressure of 250 Torr.

[0215] Example 6

[0216] This embodiment provides a deep ultraviolet light emitting diode epitaxial wafer, referring to Figure 1 、 Figure 2 It includes a substrate 1 and a buffer layer 2, an undoped AlGaN layer 3, an N-type AlGaN layer 4, a multi-quantum well layer 5, an electron blocking layer 6, a P-type AlGaN layer 7 and a P-type contact layer 8 deposited in sequence on the substrate 1.

[0217] Wherein, the substrate 1 is a sapphire substrate.

[0218] The buffer layer 2 includes an AlON layer 21, an AlN layer 22, and a Ga-doped AlN layer 23 sequentially deposited on the substrate 1. The O component in the AlON layer 21 is 0.09, and the thickness of the AlON layer 21 is 20 nm. The thickness of the AlN layer is 30 nm. The Ga component in the Ga-doped AlN layer 23 gradually decreases from 0.9 to 0.2 (from the AlN layer 22 side to the undoped AlGaN layer 3 side), and the thickness of the Ga-doped AlN layer 23 is 50 nm.

[0219] The thickness of the non-doped AlGaN layer 3 is 2.5 μm, the thickness of the N-type AlGaN layer 4 is 2.8 μm, and the Si doping concentration is 2.5×10 19 cm -3 .

[0220] Among them, the multi-quantum well layer is an alternately stacked Al x Ga 1-x N quantum well layer (x = 0.45) and Al y Ga 1-y N quantum barrier layer (y=0.55), the number of stacking periods is 9. Single Al x Ga 1-x The thickness of the N quantum well layer is 3.5nm, and the single Al y Ga 1-y The thickness of the N quantum barrier layer is 11 nm.

[0221] The electron blocking layer 6 is Al a Ga 1-a The thickness of the N layer (a=0.65) is 30 nm. The thickness of the P-type AlGaN layer 7 is 150 nm, and the Mg doping concentration is 5×10 19 cm -3 The P-type contact layer 8 is a P-type doped AlGaN layer with a Mg doping concentration of 1×10 20cm -3 , with a thickness of 20nm.

[0222] The preparation method of the deep ultraviolet light-emitting diode epitaxial wafer in this embodiment is as follows:

[0223] (1) providing a substrate;

[0224] (2) growing an AlON layer on a substrate;

[0225] Specifically, the AlON layer was sputtered in PVD with a sputtering power of 3.5 kW, a sputtering temperature of 600° C., a sputtering pressure of 15 torr, and a sputtering atmosphere of a mixed gas of N 2 , Ar, and O 2 (the volume ratio of the three being 6:18:1).

[0226] (3) growing an AlN layer on the AlON layer;

[0227] Specifically, the AlN layer was sputtered in PVD with a sputtering power of 3.5 kW, a sputtering temperature of 600° C., a sputtering pressure of 15 torr, and a sputtering atmosphere of a mixed gas of N 2 and Ar (the volume ratio of the two being 1:6).

[0228] (4) subjecting the substrate to high temperature treatment;

[0229] Specifically, the heat treatment is performed in MOCVD at a temperature of 1400° C., in an H 2 atmosphere, and at a pressure of 100 torr.

[0230] (5) growing a Ga-doped AlN layer on the AlN layer;

[0231] Specifically, the Ga-doped AlN layer was grown by MOCVD at a growth temperature of 1000° C., a growth pressure of 100 torr, and a growth atmosphere of a mixed gas of N 2 and NH 3 (the volume ratio of the two being 3:1).

[0232] (6) growing a non-doped AlGaN layer on the Ga-doped AlN layer;

[0233] Specifically, the non-doped AlGaN layer is grown by MOCVD at a growth temperature of 1200° C. and a growth pressure of 100 Torr.

[0234] (7) an N-type AlGaN layer on the non-doped AlGaN layer;

[0235] Specifically, MOCVD is used to grow the N-type AlGaN layer at a growth temperature of 1200° C. and a growth pressure of 100 Torr.

[0236] (8) growing a multi-quantum well layer on the N-type AlGaN layer;

[0237] Specifically, MOCVD is used to periodically grow multiple Alx Ga 1-x N quantum well layer and Al y Ga 1-y N quantum barrier layer. Among them, Al x Ga 1-x The growth temperature of the N quantum well layer is 900℃ and the growth pressure is 200torr. y Ga 1-y The growth temperature of the N quantum barrier layer is 1100°C and the growth pressure is 200 torr.

[0238] (9) growing an electron blocking layer on the multi-quantum well layer;

[0239] Specifically, the electron blocking layer is grown by MOCVD at a growth temperature of 1050° C. and a growth pressure of 200 Torr.

[0240] (10) growing a P-type AlGaN layer on the electron blocking layer;

[0241] Specifically, the P-type AlGaN layer is grown by MOCVD at a growth temperature of 1050° C. and a growth pressure of 300 Torr.

[0242] (11) growing a P-type contact layer on the P-type AlGaN layer;

[0243] Specifically, the P-type contact layer is grown by MOCVD at a growth temperature of 1040° C. and a growth pressure of 250 Torr.

[0244] Example 7

[0245] This embodiment provides a deep ultraviolet light emitting diode epitaxial wafer, referring to Figure 1 、 Figure 2 It includes a substrate 1 and a buffer layer 2, an undoped AlGaN layer 3, an N-type AlGaN layer 4, a multi-quantum well layer 5, an electron blocking layer 6, a P-type AlGaN layer 7 and a P-type contact layer 8 deposited in sequence on the substrate 1.

[0246] Wherein, the substrate 1 is a sapphire substrate.

[0247] The buffer layer 2 includes an AlON layer 21, an AlN layer 22, and a Ga-doped AlN layer 23 sequentially deposited on the substrate 1. The O component in the AlON layer 21 is 0.09, and the thickness of the AlON layer 21 is 20 nm. The thickness of the AlN layer is 30 nm. The Ga component in the Ga-doped AlN layer 23 gradually decreases from 0.9 to 0.2 (from the AlN layer 22 side to the undoped AlGaN layer 3 side), and the thickness of the Ga-doped AlN layer 23 is 50 nm.

[0248] The thickness of the non-doped AlGaN layer 3 is 2.5 μm, the thickness of the N-type AlGaN layer 4 is 2.8 μm, and the Si doping concentration is 2.5×10 19 cm -3 .

[0249] Among them, the multi-quantum well layer is an alternately stacked Al x Ga 1-x N quantum well layer (x = 0.45) and Al y Ga 1-y N quantum barrier layer (y=0.55), the number of stacking periods is 9. Single Al x Ga 1-x The thickness of the N quantum well layer is 3.5nm, and the single Al y Ga 1-y The thickness of the N quantum barrier layer is 11 nm.

[0250] The electron blocking layer 6 is Al a Ga 1-a The thickness of the N layer (a=0.65) is 30 nm. The thickness of the P-type AlGaN layer 7 is 150 nm, and the Mg doping concentration is 5×10 19 cm -3 The P-type contact layer 8 is a P-type doped AlGaN layer with a Mg doping concentration of 1×10 20 cm -3 , with a thickness of 20nm.

[0251] The preparation method of the deep ultraviolet light-emitting diode epitaxial wafer in this embodiment is as follows:

[0252] (1) providing a substrate;

[0253] (2) growing an AlON layer on a substrate;

[0254] Specifically, the AlON layer was sputtered in PVD with a sputtering power of 3.5 kW, a sputtering temperature of 600° C., a sputtering pressure of 15 torr, and a sputtering atmosphere of a mixed gas of N 2 , Ar, and O 2 (the volume ratio of the three being 6:18:1).

[0255] (3) growing an AlN layer on the AlON layer;

[0256] Specifically, the AlN layer was sputtered in PVD with a sputtering power of 3.5 kW, a sputtering temperature of 600° C., a sputtering pressure of 15 torr, and a sputtering atmosphere of a mixed gas of N 2 , Ar, and O 2 (the volume ratio of the three being 6:18:1).

[0257] (4) subjecting the substrate to high temperature treatment;

[0258] Specifically, the heat treatment is performed in MOCVD at a temperature of 1100° C., in an H 2 atmosphere, and at a pressure of 100 torr.

[0259] (5) growing a Ga-doped AlN layer on the AlN layer;

[0260] Specifically, the Ga-doped AlN layer is grown by MOCVD at a growth temperature of 1000° C., a growth pressure of 100 torr, and a growth atmosphere of a mixed gas of N 2 , NH 3 , and H 2 (the volume ratio of the three is 6:2:1).

[0261] (6) growing a non-doped AlGaN layer on the Ga-doped AlN layer;

[0262] Specifically, the non-doped AlGaN layer is grown by MOCVD at a growth temperature of 1200° C. and a growth pressure of 100 Torr.

[0263] (7) an N-type AlGaN layer on the non-doped AlGaN layer;

[0264] Specifically, MOCVD is used to grow the N-type AlGaN layer at a growth temperature of 1200° C. and a growth pressure of 100 Torr.

[0265] (8) growing a multi-quantum well layer on the N-type AlGaN layer;

[0266] Specifically, MOCVD is used to periodically grow multiple Al x Ga 1-x N quantum well layer and Al y Ga 1-y N quantum barrier layer. Among them, Al x Ga 1-x The growth temperature of the N quantum well layer is 900℃ and the growth pressure is 200torr. y Ga 1-y The growth temperature of the N quantum barrier layer is 1100°C and the growth pressure is 200 torr.

[0267] (9) growing an electron blocking layer on the multi-quantum well layer;

[0268] Specifically, the electron blocking layer is grown by MOCVD at a growth temperature of 1050° C. and a growth pressure of 200 Torr.

[0269] (10) growing a P-type AlGaN layer on the electron blocking layer;

[0270] Specifically, the P-type AlGaN layer is grown by MOCVD at a growth temperature of 1050° C. and a growth pressure of 300 Torr.

[0271] (11) growing a P-type contact layer on the P-type AlGaN layer;

[0272] Specifically, the P-type contact layer is grown by MOCVD at a growth temperature of 1040° C. and a growth pressure of 250 Torr.

[0273] Comparative Example 1

[0274] The difference between this comparative example and Example 1 is that the buffer layer is only a 100 nm thick AlN layer sputtered by PVD, and no AlON layer and Ga-doped AlN layer are provided. Accordingly, the steps for preparing the AlON layer and Ga-doped AlN layer are not provided. All other steps are the same as Example 1.

[0275] Comparative Example 2

[0276] The difference between this comparative example and Example 1 is that the buffer layer is only an AlON layer and an AlN layer, and no Ga-doped AlN layer is provided. Accordingly, the preparation step of the Ga-doped AlN layer is not provided. The rest is the same as Example 1.

[0277] The brightness of the deep ultraviolet light-emitting diode epitaxial wafers obtained in Examples 1-7 and Comparative Examples 1-2 was tested, and the light efficiency improvement rates of the other examples and comparative examples were calculated based on the epitaxial wafer in Comparative Example 1. The specific results are shown in the following table:

[0278] The specific results are as follows:

[0279]

[0280]

[0281] It can be seen from the table that when the buffer layer of the present invention is introduced into the epitaxial structure, the luminous efficiency can be effectively improved.

[0282] The above is a preferred embodiment of the invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A deep ultraviolet light-emitting diode epitaxial wafer, characterized in that: The invention comprises a substrate and a buffer layer, an undoped AlGaN layer, an N-type AlGaN layer, a multi-quantum well layer, an electron blocking layer, a P-type AlGaN layer and a P-type contact layer sequentially deposited on the substrate; wherein the buffer layer comprises an AlON layer, an AlN layer and a Ga-doped AlN layer sequentially deposited on the substrate; the proportion of the O component in the AlON layer is 0.07-0.1; and the substrate is a sapphire substrate; The AlON and AlN layers are sputtered by PVD with a sputtering power of 2-5kW, a sputtering temperature of 300-800°C, and a sputtering pressure of 1-50 torr. After the AlON and AlN layers are sputtered, MOCVD is used for treatment with a H2 atmosphere, a treatment temperature of 1000-1300°C, and a pressure of 50-500 torr. The sputtering atmosphere of the AlON layer is a mixed gas of N2, Ar and O2, and the volume ratio of N2, Ar and O2 is (1-10): (5-30): 1; the sputtering atmosphere of the AlN layer is a mixed gas of N2 and Ar; wherein, the volume ratio of N2 and Ar is 1: (1-10).

2. The deep ultraviolet light-emitting diode epitaxial wafer according to claim 1, wherein: The thickness of the AlON layer is 5-50 nm.

3. The deep ultraviolet light-emitting diode epitaxial wafer according to claim 1, wherein: The thickness of the AlN layer is 10-100 nm, and the thickness of the Ga-doped AlN layer is 10-100 nm.

4. The deep ultraviolet light-emitting diode epitaxial wafer according to claim 1, wherein: The proportion of Ga component in the Ga-doped AlN layer is 0.01-0.

1.

5. The deep ultraviolet light-emitting diode epitaxial wafer according to claim 1, wherein: The content of Ga component in the Ga-doped AlN layer is greater than the content of Ga component in the undoped AlGaN layer; The content of the Ga component in the Ga-doped AlN layer gradually decreases from the AlN layer side to the content of the Ga component in the non-doped AlGaN layer.

6. A method for preparing a deep ultraviolet light-emitting diode epitaxial wafer, for preparing the deep ultraviolet light-emitting diode epitaxial wafer according to any one of claims 1 to 5, characterized in that: include: (1) providing a substrate; (2) sequentially growing a buffer layer, an undoped AlGaN layer, an N-type AlGaN layer, a multi-quantum well layer, an electron blocking layer, a P-type AlGaN layer, and a P-type contact layer on the substrate; The buffer layer includes an AlON layer, an AlN layer and a Ga-doped AlN layer sequentially arranged on the substrate.

7. The method for preparing a deep ultraviolet light-emitting diode epitaxial wafer according to claim 6, wherein: In step (2), the Ga-doped AlN layer is grown by MOCVD at a growth temperature of 800-1200° C., a growth pressure of 50-500 torr, and a growth atmosphere of a mixed gas of N 2 and NH 3 ; wherein the volume ratio of N 2 to NH 3 is (1-10):

1.

8. A deep ultraviolet light-emitting diode, characterized in that: It comprises the deep ultraviolet light-emitting diode epitaxial wafer as described in any one of claims 1 to 5.

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