Algainp yellow-green LED epitaxial wafer with high brightness, low leakage and high reliability

Abstract

Disclosed in the present invention is an AlGaInP yellow-green LED epitaxial wafer with high brightness, low leakage and high reliability. The epitaxial wafer comprises an N-type GaAs buffer layer, an N-type GaInP etch-stop layer, an N-type GaAs ohmic contact layer, an N-type AlGaInP current spreading layer, an N-type electron retardation layer, an N-type AlInP confinement layer, a multiple quantum well layer, a P-type AlInP confinement layer, a P-type GaP current spreading layer and a P-type GaP ohmic contact layer, which are sequentially grown on a GaAs substrate. An electron retardation layer, a graded quantum barrier thickness design, and a magnesium diffusion barrier layer are introduced, so as to effectively suppress electron leakage and magnesium diffusion, thereby reducing non-radiative recombination, and thus significantly improving the luminous efficiency and high-temperature operating stability of LEDs.

Description

A high-brightness, low-leakage, and highly reliable aluminum gallium indium phosphor yellow-green LED epitaxial wafer

[0001] This application claims priority to Chinese Patent Application No. 202411977272.7, filed with the State Intellectual Property Office of China on December 31, 2024, entitled "A High-Brightness, Low-Leakage, and High-Reliability AlGaInP Yellow-Green LED Epitaxial Wafer", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to the field of light-emitting diode (LED) technology, specifically to an aluminum gallium indium phosphorus (AlGaInP) yellow-green LED epitaxial wafer with high brightness, low leakage, and high reliability. Background Technology

[0003] AlGaInphosphorus (AlGaInphosphorus) yellow-green LED chips offer efficient, energy-saving, and environmentally friendly lighting solutions for home, commercial, and public lighting. Furthermore, they can be used to manufacture high-resolution, high-color-fidelity displays, enhancing the realism and detail of the visual experience. Simultaneously, yellow-green LED chips possess high-speed, high-efficiency data transmission capabilities, which are of great significance to the development of modern communication networks in the field of optical communication. These superior performance characteristics rely on the unique advantages of the AlGaInphosphorus material system and its complex epitaxial structure design; the rationality of the epitaxial structure directly affects the chip's performance and application range.

[0004] Existing quaternary aluminum gallium indium phosphide (AlGaInP) short-wavelength LED epitaxial structures typically include: a gallium arsenide (GaAs) substrate, followed by sequentially grown N-type GaAs buffer layer, N-type GaInP etch stop layer, N-type GaAs ohmic contact layer, N-type AlGaInP current spreading layer, N-type AlInP confinement layer, multiple quantum well layer, P-type AlInP confinement layer, P-type GaP current spreading layer, and P-type GaP ohmic contact layer. This structure exhibits good luminous efficiency and high reliability in practical applications. However, in the development towards shorter wavelengths, the material system faces many challenges, particularly the significant impact of aluminum content variations on device performance.

[0005] As the Al content in the multi-quantum-well layer increases, the AlGaInphosphorus material gradually transitions from a direct bandgap to an indirect bandgap, requiring phonon participation in the luminescence process. This significantly reduces the quantum efficiency of recombination luminescence and decreases the probability of electron-hole recombination. Furthermore, because electrons migrate much faster than holes, a large number of electrons easily leak into the P-type semiconductor region under non-equilibrium conditions, increasing nonradiative recombination. This not only leads to a decrease in luminescence efficiency but also causes a large amount of heat to accumulate in the interface layer region, narrowing the semiconductor's bandgap and further exacerbating electron leakage.

[0006] On the other hand, under high-temperature operating conditions, magnesium in P-type doping easily diffuses into the quantum well region, forming impurity energy levels, trapping electrons, and further increasing non-radiative recombination, leading to a continuous decrease in the luminous efficiency of the quantum well. Furthermore, as the device's operating time increases, this effect gradually accumulates, causing a continuous decline in device brightness and a significant reduction in reliability. This coupling effect of electron leakage and magnesium diffusion creates a vicious cycle, severely restricting the performance improvement and stability of short-wavelength AlGaInPT LED devices. Summary of the Invention

[0007] To address the above problems, this invention provides an improved high-brightness yellow-green wavelength quaternary aluminum gallium indium phosphide epitaxial wafer.

[0008] The specific technical solution of the present invention is as follows:

[0009] A high-brightness, low-leakage, and highly reliable aluminum gallium indium phosphor yellow-green LED epitaxial wafer is characterized by comprising the following layer structures sequentially grown on a gallium arsenide substrate:

[0010] The N-type gallium arsenide buffer layer has a thickness of 150-200 nanometers, a Si doping concentration of 1 × 10¹⁸-2 × 10¹⁸ atoms / cubic centimeter, and a dopant of disilane.

[0011] The N-type gallium indium phosphide etch stop layer has a thickness of 100-200 nanometers, a Si doping concentration of 1 × 10¹⁸-3 × 10¹⁸ atoms / cubic centimeter, and a dopant of disilane.

[0012] The N-type gallium arsenide ohmic contact layer has a thickness of 30-100 nanometers, a carrier concentration of 3 × 10¹⁸-6 × 10¹⁸ per cubic centimeter, and is doped with disilane.

[0013] The N-type aluminum gallium indium phosphide current spreading layer has a thickness of 1000-2500 nanometers and a composition of (Al) x Ga 1-x ) 0.5 In 0.5 P, 0.6≤x≤1, carrier concentration of 13 × 10¹⁸ per cubic centimeter, dopant is disilane;

[0014] The N-type electron retarding layer has a multilayer superlattice structure and is composed of Al. y Ga 1-y The N-type electron retarding layer consists of sublayers of InP (0.6≤y≤0.8), Al₀.₅In₀.₅P, and Al₀.₆₅In₀.₃₅P. The thickness of each sublayer increases progressively along the epitaxial growth direction, specifically determined by the following formula: Thickness of the nth layer = Initial thickness + (Maximum thickness / Total number of layers) × (n-1), where:

[0015] Al y Ga 1-y The maximum thickness of the InP sublayer is 10-20 nanometers, and the initial thickness is 3-5 nanometers.

[0016] Al 0.5 In 0.5 The maximum thickness of the P sublayer is 15-25 nanometers, and the initial thickness is 5-7 nanometers.

[0017] Al 0.65 In 0.35 The maximum thickness of the P sublayer is 5-10 nanometers, and the initial thickness is 1-3 nanometers;

[0018] The total number of layers is 10-25 pairs, the Si element doping concentration is 1 × 10¹⁸-2 × 10¹⁸ atoms / cubic centimeter, and the dopant is disilane;

[0019] The N-type aluminum indium phosphide confinement layer has a thickness of 150-350 nm, a carrier concentration of 7 × 10¹⁷-2 × 10¹⁸ per cubic centimeter, and the dopant is disilane;

[0020] Multiple quantum well layers, containing 30-80 pairs of quantum wells and quantum barriers, wherein:

[0021] Each quantum well is 3-5 nanometers thick;

[0022] The thickness of the quantum barrier decreases layer by layer from 10-15 nanometers to 4-6 nanometers along the growth direction;

[0023] The Al content of the quantum barrier is from Al a Ga 1-a InP (0.6≤a≤0.7) gradually increases to Al b Ga 1-b InP (0.8≤b≤0.9);

[0024] A p-type aluminum indium phosphide (AIP) confinement layer with a thickness of 250-600 nm is formed. A magnesium diffusion barrier layer with a thickness of 50-150 nm is formed along the thickness direction of the P-type AIP confinement layer. The magnesium diffusion barrier layer has a magnesium doping concentration of 1 × 10¹⁷-3 × 10¹⁷ atoms / cm³, and the carrier concentration of the remaining portion is 8 × 10¹⁷-1.5 × 10¹⁸ per cm³. The dopant is magnesia-dicenocene.

[0025] P-type gallium phosphide current spreading layer, divided into:

[0026] The bottom layer is low-magnesium doped with a thickness of 200-300 nm and a magnesium doping concentration of 3 × 10¹⁷-5 × 10¹⁷ atoms / cm³. The top layer is high-magnesium doped with a thickness of 300-1500 nm and a magnesium doping concentration of 4-8 × 10¹⁸ atoms / cm³. The dopant is magnesia-dicerocene.

[0027] A p-type gallium phosphide ohmic contact layer with a thickness of 30-100 nm and a carrier concentration of 0.5 × 10⁻⁶ nm. 19 -2 × 10 20 The dopant is carbon tetrabromide or carbon tetrachloride per cubic centimeter.

[0028] Preferably, the thickness of the aluminum gallium indium phosphide current spreading layer is 1500-2000 nanometers, and x ranges from 0.7 to 0.9.

[0029] Preferably, the total number of N-type electron delay layers is 15-20 pairs, and the thickness of each sub-layer is designed according to the formula: thickness of the nth layer = initial thickness + maximum thickness / total number of layers × (n-1).

[0030] Preferably, the dopant of the N-type electron delay layer is disilane, and the doping concentration is 1.5 × 10¹⁸ - 2 × 10¹⁸ atoms / cm³.

[0031] Preferably, the number of quantum wells and quantum barriers in the multi-quantum well layer is 40-60 pairs, the thickness of the quantum wells in the multi-quantum well layer is 4-5 nanometers, and the thickness of the quantum barriers in the multi-quantum well layer gradually decreases from 10 nanometers to 5 nanometers. The Al element content in the direction pointing towards the P-type aluminum indium phosphide confinement layer decreases from Al... a Ga 1-a InP (0.65≤a≤0.7) gradually increases to Al b Ga 1-b InP (0.85≤b≤0.9).

[0032] Preferably, the magnesium diffusion barrier layer in the P-type aluminum indium phosphide confinement layer has a thickness of 80-120 nanometers and a doping concentration of 1.5 × 10¹⁷-2.5 × 10¹⁷ atoms / cubic centimeter. If the magnesium diffusion barrier layer is too thick or the doping is too low, it will affect hole injection. If the thickness is too thin or the doping is too high, it will not be able to block magnesium.

[0033] Preferably, the magnesium diffusion barrier layer is disposed at one-third of the distance from the side of the P-type aluminum indium phosphide confinement layer closest to the multi-quantum well layer. With the adjustment of the thickness and doping concentration of the magnesium diffusion barrier layer, if it is far from the quantum well and close to the P-type gallium phosphide current spreading layer, the magnesium will diffuse too much and will bypass the barrier layer, thus failing to play its role and causing reliability issues; if it is closer to the quantum well layer, it will lead to insufficient hole injection, affecting the quantum injection efficiency.

[0034] Preferably, the thickness of the low-doped layer of the P-type gallium phosphide current spreading layer is 250-300 nanometers, and the magnesium doping concentration is 4 × 10¹⁷-5 × 10¹⁷ atoms / cubic centimeter.

[0035] Preferably, the thickness of the highly doped layer of the P-type gallium phosphide current spreading layer is 500-1000 nanometers, and the magnesium doping concentration is 5 × 10¹⁸-7 × 10¹⁸ atoms / cubic centimeter.

[0036] Preferably, the thickness of the P-type gallium phosphide ohmic contact layer is 50-80 nanometers, and the dopant is carbon tetrabromide.

[0037] Through the above technical solutions, the present invention achieves the following beneficial effects:

[0038] Improving electron mobility efficiency and limiting electron leakage: By introducing an N-type electron retarder layer, the electron mobility is significantly reduced through the superlattice structure and the gradient change of Al content, reducing electron leakage to the P-region and improving the recombination efficiency of electrons and holes; through the thickness gradient design, the electron retarder layer further optimizes the electron transport path as the thickness gradually increases, effectively reducing the occurrence of nonradiative recombination.

[0039] Optimizing the luminescence efficiency of the multi-quantum-well layer: The thickness of the quantum barrier layer is gradually reduced from 10-15 nm to 4-6 nm, effectively improving the hole injection efficiency. Simultaneously, by gradually increasing the Al content in the quantum barrier layer, the bandgap is gradually increased, optimizing the efficiency of synchronous arrival of electrons and holes at the luminescent layer, thereby increasing the probability of radiative recombination. The purpose of this design is to adjust the position of the main luminescent layer to the center of the quantum well layer, thereby improving luminescence efficiency.

[0040] Suppressing magnesium diffusion and improving device stability: A lightly doped magnesium diffusion barrier layer is incorporated into the P-type aluminum indium phosphide layer. This barrier effect effectively reduces the amount of magnesium diffusing into the light-emitting layer, thereby minimizing non-radiative recombination caused by magnesium impurity energy levels. The thickness and doping concentration of the barrier layer are precisely designed to balance suppressing magnesium diffusion with maintaining hole injection efficiency.

[0041] Improve the performance of the P-type gallium phosphide current spread layer: The P-type gallium phosphide current spread layer is designed as two parts, with the lower layer being less doped to reduce the probability of magnesium diffusion into the light-emitting layer, and the upper layer being more doped to enhance the current spread capability and hole injection efficiency, thereby further improving the light-emitting performance of the device.

[0042] Significantly improves device brightness and reliability: Multiple innovative designs work together to significantly increase the recombination probability of electrons and holes, reduce carrier leakage and nonradiative recombination, and greatly improve the brightness and reliability of AlGaInphos short-wavelength LEDs, especially showing greater stability under high-temperature conditions.

[0043] In summary, this invention solves the problems of brightness decay and insufficient device reliability in the prior art, giving the aluminum gallium indium phosphorus yellow-green LED chip of this invention significant advantages in luminous efficiency and stability. Attached Figure Description

[0044] Figure 1 is a schematic diagram of the structure of the high-brightness, low-leakage, and high-reliability aluminum gallium indium phosphor yellow-green LED epitaxial wafer of the present invention.

[0045] Figure 2 is a graph showing the relationship between the thickness of each sublayer of the N-type electron delay layer in Embodiment 1 of the present invention and the gradual linear increase of the number of layers.

[0046] Figure 3 is a schematic diagram of the structure of the P-type aluminum indium phosphide confinement layer in this invention.

[0047] Figure 4 is a schematic diagram of the structure of the P-type gallium phosphide current spreading layer in this invention.

[0048] Figure 5 shows the relationship between the forward voltage and forward current of a 14mil yellow-green LED (in this invention embodiment and conventional).

[0049] Figure 6 is a wavelength-current curve of a 14mil yellow-green LED (in this invention embodiment and conventional).

[0050] Figure 7 shows the relationship between the luminous intensity of a 14mil yellow-green LED and the forward current (in this invention embodiment and conventional).

[0051] Figure 8 shows a comparison of the ΔLOP of a 14mil yellow-green LED at room temperature and high temperature over time (the embodiment of this invention and the conventional method). Detailed Implementation

[0052] The preferred embodiments of the present invention are given below with reference to the accompanying drawings to illustrate the technical solution of the present invention in detail.

[0053] Example 1

[0054] As shown in Figure 1, this embodiment provides a high-brightness, low-leakage, and highly reliable aluminum gallium indium phosphor yellow-green LED epitaxial wafer, the specific structure and parameters of which are as follows:

[0055] The N-type gallium arsenide buffer layer L1 has a thickness of 200 nanometers, a doping concentration of 1.5 × 10¹⁸ atoms / cubic centimeter, and uses disilane as the dopant.

[0056] N-type gallium indium phosphide etch stop layer L2: 150 nm thick, doped at a concentration of 2 × 10¹⁸ atoms / cm³, with disilane as the dopant;

[0057] N-type gallium arsenide ohmic contact layer L3: 50 nm thick, carrier concentration of 4 × 10¹⁸ per cubic centimeter, dopant is disilane;

[0058] N-type aluminum gallium indium phosphide current spreading layer L4: 2000 nm thick, composition is (Al... x Ga 1-x ) 0.5 In 0.5 P, where x = 0.7, and the carrier concentration is 2 × 10¹⁸ per cubic centimeter;

[0059] N-type electron retarder L5: It adopts a multilayer superlattice structure with a total of 20 pairs of layers. The thickness of each sublayer increases sequentially along the growth direction, as shown in Figure 2.

[0060] The maximum thickness of the AlyGa1-yInP sublayer is 15 nanometers, and the initial thickness is 4 nanometers.

[0061] Al 0.5 In 0.5 The maximum thickness of the P sublayer is 20 nanometers, and the initial thickness is 6 nanometers;

[0062] Al 0.65 In 0.35 The maximum thickness of the P sublayer is 8 nanometers, and the initial thickness is 2 nanometers;

[0063] N-type aluminum indium phosphide confinement layer L6: 300 nm thick, with a doping concentration of 1 × 10¹⁸ atoms / cm³;

[0064] The electron retarding layer utilizes the fact that the mobility of Al gallium indium phosphide (AlGaInP) varies with the Al content. The higher the Al content, the lower the mobility. In particular, the last layer in the three groups has a high Al content and a high bandgap, which has a stronger restriction on electrons and can effectively reduce electron mobility.

[0065] L7 multi-quantum-well layer: Contains 60 pairs of quantum wells and quantum barriers. Specific parameters:

[0066] The quantum well thickness is 4 nanometers, and the quantum barrier thickness decreases linearly from 12 nanometers to 5 nanometers, which can improve hole injection;

[0067] Al element content from Al a Ga 1-a InP (a = 0.65) gradually increases to Al b Ga 1-b InP (b = 0.85); As the Al content increases, the band gap of the quantum barrier layer gradually increases, which can slow down the migration speed of electrons. Its equivalent efficiency is to move the position of the main emitting layer towards the center of the emitting layer, increase the simultaneous rate of electrons and holes reaching the emitting layer, and increase the probability of radiative recombination.

[0068] P-type aluminum indium phosphide confinement layer L8: with a thickness of 500 nanometers, as shown in Figure 3, including a lower P-type aluminum indium phosphide barrier layer L71, a magnesium diffusion barrier layer L72 with a thickness of 50 nanometers and a doping concentration of 1×10¹⁷ atoms / cubic centimeter at one-third of the thickness direction, and an upper P-type aluminum indium phosphide confinement layer L73.

[0069] P-type gallium phosphide current spreading layer L9: As shown in Figure 4, it is divided into two parts:

[0070] Bottom low-magnesium doped layer L91: 200 nm thick, doping concentration of 4 × 10¹⁷ atoms / cm³;

[0071] The top high-magnesium doped layer L92 has a thickness of 1000 nanometers and a doping concentration of 6 × 10¹⁸ atoms / cubic centimeter;

[0072] P-type gallium phosphide ohmic contact layer L10: 50 nm thick, carrier concentration of 1 × 10²⁰ per cubic centimeter, dopant is carbon tetrabromide.

[0073] Example 2

[0074] Based on Example 1, the following parameters are adjusted:

[0075] N-type electron retarder: The total number of layers has been reduced from 20 pairs to 15 pairs;

[0076] Multiple quantum well layers: The number of quantum well barrier pairs is reduced from 60 pairs to 50 pairs;

[0077] P-type aluminum indium phosphide confinement layer: The thickness of the magnesium diffusion barrier layer is adjusted to 100 nanometers, and the doping concentration is 2 × 10¹⁷ atoms / cubic centimeter.

[0078] P-type gallium phosphide current spreading layer: The thickness of the low-magnesium doped layer was changed to 300 nanometers.

[0079] Example 3

[0080] Based on Example 2, the parameters were further optimized:

[0081] N-type electron retardation layer: employs an 18-pair superlattice structure;

[0082] Multiple quantum well layers: the Al content of the quantum barrier gradually increases from AlaGa1-aInP (a = 0.7) to AlbGa1-bInP (b = 0.9); the thickness of the quantum barrier decreases linearly to 4 nanometers;

[0083] P-type gallium phosphide current spreading layer: The thickness of the low magnesium doped layer was changed to 250 nanometers.

[0084] Test experiment:

[0085] 1. Device fabrication and testing

[0086] Epitaxial wafers with conventional structures and in Examples 1, 2 and 3 were prepared using metal-organic chemical vapor deposition (MOCVD).

[0087] The light output power and spectral distribution of the device are measured using electroluminescence (EL) spectroscopy.

[0088] The leakage current of a device can be evaluated by measuring its carrier leakage characteristics using IV curves.

[0089] The reliability and brightness degradation of the device under high temperature conditions were evaluated through high-temperature aging tests.

[0090] 2. Experimental results: As shown in Figures 5-8, Table 1 shows the data when the test current is 60mA.

[0091] Parameter description:

[0092] VF (V): Forward Voltage, measured in volts (V).

[0093] WLD (nanometer): Dominant wavelength, measured in nanometers (nanometers).

[0094] LOP (mcd): Luminous Output Power, measured in millicandelas (mcd).

[0095] It can be seen that:

[0096] Brightness enhancement effect:

[0097] The optical output power of the device in Example 1 is increased by about 15% compared with the conventional structure, and it maintains stable output at 60°C.

[0098] Examples 2 and 3 further optimized the Al content and magnesium diffusion suppression effect, resulting in a 18% and 20% increase in brightness compared to the traditional structure, respectively.

[0099] Carrier leakage suppression:

[0100] Experiments show that the N-type electron delay layer effectively suppresses electron leakage. Under the same quantum well logarithm, the saturation current of Example 1 is 10 mA higher than that of the conventional structure.

[0101] High temperature stability:

[0102] After 1000 hours of continuous aging at 75mA in an 85°C environment, the brightness decay of Example 1 was only 4%, while that of conventional devices was as high as 17%.

[0103] Examples 2 and 3 showed a brightness attenuation of 3% and 2.5% respectively in this test, demonstrating higher reliability.

[0104] 3. Experimental Conclusions

[0105] Through the above embodiments and experimental data verification, the aluminum gallium indium phosphor yellow-green LED epitaxial wafer provided by the present invention has the following advantages:

[0106] Significantly improves the brightness and luminous efficiency of the device;

[0107] Effectively suppresses carrier leakage and non-radiative recombination, reducing leakage current;

[0108] Improve the stability and reliability of devices in high-temperature environments;

[0109] The brightness decay of the device is further slowed down by using a magnesium diffusion barrier layer design.

Claims

1. A high-brightness, low-leakage, and high-reliability aluminum gallium indium phosphor yellow-green light-emitting diode epitaxial wafer, characterized in that, This includes the following layer structures grown sequentially on a gallium arsenide substrate: The N-type gallium arsenide buffer layer has a thickness of 150-200 nanometers, a Si doping concentration of 1 × 10¹⁸-2 × 10¹⁸ atoms / cubic centimeter, and a dopant of disilane. The N-type gallium indium phosphide etch stop layer has a thickness of 100-200 nanometers, a Si doping concentration of 1 × 10¹⁸-3 × 10¹⁸ atoms / cubic centimeter, and a dopant of disilane. The N-type gallium arsenide ohmic contact layer has a thickness of 30-100 nanometers, a carrier concentration of 3 × 10¹⁸-6 × 10¹⁸ per cubic centimeter, and is doped with disilane. The N-type aluminum gallium indium phosphide current spreading layer has a thickness of 1000-2500 nanometers and a composition of (Al) x Ga 1-x ) 0.5 In 0.5 P, where 0.6≤x≤1, carrier concentration is 1 × 10¹⁸-3 × 10¹⁸ per cubic centimeter, and dopant is disilane; The N-type electron retarding layer has a multilayer superlattice structure and is composed of Al. y Ga 1-y InP (0.6≤y≤0.8), Al 0.5 In 0.5 P, Al 0.65 In 0.35 The N-type electron retarder layer consists of P-layers, and the thickness of each sublayer increases progressively along the epitaxial growth direction, specifically determined by the following formula: Thickness of the nth layer = Initial thickness + (Maximum thickness / Total number of layers) × (n-1), where: Al y Ga 1-y The maximum thickness of the InP sublayer is 10-20 nanometers, and the initial thickness is 3-5 nanometers. The maximum thickness of the Al₀.₅In₀.₅P sublayer is 15-25 nanometers, and the initial thickness is 5-7 nanometers; The maximum thickness of the Al₀.₆₅In₀.₃₅P sublayer is 5-10 nanometers, and the initial thickness is 1-3 nanometers; The total number of layers is 10-25 pairs, the Si element doping concentration is 1 × 10¹⁸-2 × 10¹⁸ atoms / cubic centimeter, and the dopant is disilane; The N-type aluminum indium phosphide confinement layer has a thickness of 150-350 nm, a carrier concentration of 7 × 10¹⁷-2 × 10¹⁸ per cubic centimeter, and the dopant is disilane; A multi-quantum-well layer contains 30-80 pairs of quantum wells and quantum barriers, each pair consisting of one quantum well and one quantum barrier, wherein: Each quantum well is 3-5 nanometers thick; The thickness of the quantum barrier decreases layer by layer from 10-15 nanometers to 4-6 nanometers along the growth direction; The Al content of the quantum barrier is from Al a Ga 1-a InP (0.6≤a≤0.7) gradually increases to Al b Ga 1-b InP (0.8≤b≤0.9); A p-type aluminum indium phosphide (AIP) confinement layer with a thickness of 250-600 nm is formed. A magnesium diffusion barrier layer with a thickness of 50-150 nm is formed along the thickness direction of the P-type AIP confinement layer. The magnesium diffusion barrier layer has a doping concentration of 1 × 10¹⁷-3 × 10¹⁷ atoms / cm³, and the carrier concentration of the remaining portion is 8 × 10¹⁷-1.5 × 10¹⁸ per cm³. The dopant is magnesia-dicenocene. P-type gallium phosphide current spreading layer, divided into: The bottom layer is low-magnesium doped with a thickness of 200-300 nm and a magnesium doping concentration of 3 × 10¹⁷-5 × 10¹⁷ atoms / cm³. The top layer is high-magnesium doped with a thickness of 300-1500 nm and a magnesium doping concentration of 4 × 10¹⁸-8 × 10¹⁸ atoms / cm³. The dopant is magnesia-dicerocene. A p-type gallium phosphide ohmic contact layer with a thickness of 30-100 nm and a carrier concentration of 0.5 × 10⁻⁶ nm. 19 -2 × 10 20 The dopant is carbon tetrabromide or carbon tetrachloride per cubic centimeter.

2. The aluminum gallium indium phosphor yellow-green LED epitaxial wafer according to claim 1, characterized in that, The total number of N-type electron delay layers is 15-20 pairs, and the thickness of each sub-layer is designed according to the formula: thickness of the nth layer = initial thickness + maximum thickness / total number of layers × (n-1).

3. The aluminum gallium indium phosphor yellow-green LED epitaxial wafer according to claim 1, characterized in that, The dopant for the N-type electron delay layer is disilane, with a doping concentration of 1.5 × 10¹⁸ - 2 × 10¹⁸ atoms / cm³.

4. The aluminum gallium indium phosphor yellow-green LED epitaxial wafer according to any one of claims 1, characterized in that, The number of quantum wells and quantum barriers in the multi-quantum well layer is 40-60 pairs. The thickness of the quantum wells in the multi-quantum well layer is 4-5 nanometers, and the thickness of the quantum barriers gradually decreases from 10 nanometers to 5 nanometers. The Al content decreases from Al in the direction from the quantum well layer to the P-type aluminum indium phosphide confinement layer. a Ga 1-a InP (0.65≤a≤0.7) gradually increases to Al b Ga 1-b InP (0.85≤b≤0.9).

5. The aluminum gallium indium phosphor yellow-green LED epitaxial wafer according to any one of claims 1, characterized in that, The magnesium diffusion barrier layer in the P-type aluminum indium phosphide confinement layer has a thickness of 80-120 nm and a doping concentration of 1.5 × 10¹⁷-2.5 × 10¹⁷ atoms / cm³.

6. The aluminum gallium indium phosphorus yellow-green LED epitaxial wafer according to any one of claims 1, characterized in that, The magnesium diffusion barrier layer is positioned one-third of the way from the side of the P-type aluminum indium phosphide confinement layer closest to the multi-quantum well layer.

7. The aluminum gallium indium phosphor yellow-green LED epitaxial wafer according to any one of claims 1, characterized in that, The thickness of the low-doped layer of the P-type gallium phosphide current spread layer is 250-300 nm, and the magnesium doping concentration is 4 × 10¹⁷-5 × 10¹⁷ atoms / cm³.

8. The aluminum gallium indium phosphor yellow-green LED epitaxial wafer according to any one of claims 1, characterized in that, The highly doped layer of the P-type gallium phosphide current spread layer is 500-1000 nm thick, and the magnesium doping concentration is 5 × 10¹⁸-7 × 10¹⁸ atoms / cm³.

9. The aluminum gallium indium phosphor yellow-green LED epitaxial wafer according to any one of claims 1, characterized in that, The thickness of the P-type gallium phosphide ohmic contact layer is 50-80 nanometers, and the dopant is carbon tetrabromide.

10. The aluminum gallium indium phosphor yellow-green LED epitaxial wafer according to any one of claims 1, characterized in that, The thickness of the N-type aluminum gallium indium phosphide current spreading layer is 1500-2000 nanometers, and x ranges from 0.7 to 0.9.

Images