Micro light emitting diode and method of manufacturing the same

Abstract

This disclosure provides a miniature light-emitting diode and its fabrication method, belonging to the field of optoelectronic manufacturing technology. The light-emitting diode comprises sequentially stacked n-type GaN layers, shallow well layers, multiple quantum well layers, and p-type aluminum-containing semiconductor layers; the shallow well layers comprise alternating layers of multiple In... y Ga 1‑y The N-layer and multiple GaN layers, 0.01 < Y ​​< 0.1; the multiple quantum well layer comprises multiple alternating layers of In. z Ga 1‑z The N-layer and multiple GaN layers, 0.2 < Z < 0.3. The embodiments disclosed herein can improve the problem of low carrier concentration in light-emitting diodes under low current density, thereby improving the luminous efficiency of the light-emitting diode.

Description

Technical Field

[0001] This disclosure relates to the field of optoelectronic manufacturing technology, and in particular to a micro light-emitting diode and its fabrication method. Background Technology

[0002] With the development of technology, the size of Micro LEDs has been further miniaturized and applied to human implantable sensors or as low-power monitoring sensors. This requires Micro LEDs with small size to have high external quantum efficiency at small or even extremely small operating current densities.

[0003] In related technologies, light-emitting diodes (LEDs) typically consist of an n-type layer, a multiple quantum well layer, and a p-type layer sequentially stacked on a substrate. However, when LEDs operate at low current densities, the carrier concentration is low, and an excessively high potential barrier may lead to insufficient injection efficiency, thus reducing the LED's optical power. Summary of the Invention

[0004] This disclosure provides a miniature light-emitting diode and its fabrication method, which can improve the problem of low carrier concentration in light-emitting diodes under low current density and enhance the luminous efficiency of light-emitting diodes. The technical solution is as follows:

[0005] In a first aspect, embodiments of this disclosure provide a light-emitting diode (LED), the LED comprising an n-type GaN layer, a shallow well layer, a multiple quantum well layer, and a p-type aluminum-containing semiconductor layer stacked sequentially; the shallow well layer comprising alternating layers of multiple In... y Ga 1-y The N-layer and multiple GaN layers, 0.01 < Y ​​< 0.1; the multiple quantum well layer comprises multiple alternating layers of In. z Ga 1-z N layers and multiple GaN layers, 0.2 < Z < 0.3.

[0006] Optionally, the shallow well layer comprises 3 to 20 layers of In y Ga 1-y N layers and 3 to 20 GaN layers; in the shallow well layer, In y Ga 1-y The N layer is Si-doped, and In y Ga 1-y The doping concentration of the N-layer is 1×10⁻⁶. 17 cm -3 Up to 1×10 18 cm -3 The GaN layer is Si-doped, and the doping concentration of the GaN layer is 1.5 × 10⁻⁶. 17 cm -3 Up to 1×10 18 cm -3 .

[0007] Optionally, the multi-quantum-well layer comprises 3 to 10 layers of In z Ga 1-z N layers and 3 to 10 GaN layers; in the multi-quantum well layer, In z Ga 1-z The N-layer is undoped, the GaN-layer is Si-doped, and the doping concentration of the GaN-layer is 1×10⁻⁶. 17 cm -3 Up to 1×10 18 cm -3 .

[0008] Optionally, the p-type aluminum-containing semiconductor layer comprises alternating layers of In... w Ga 1-w N layers and multiple Al E Ga 1-E N-layer, 0.0001 < W < 0.05, 0.005 < E < 0.2; or, the p-type aluminum-containing semiconductor layer comprises alternating layers of multiple GaN layers and multiple Al layers. E Ga 1-E N layer, 0.005<E<0.2.

[0009] Optionally, the p-type aluminum-containing semiconductor layer includes 2 to 15 layers of In. w Ga 1-w N layers and Al layers 2 to 15 E Ga 1-E N-layer; In the p-type aluminum-containing semiconductor layer, In w Ga 1-w The N layer is Mg-doped, and In w Ga 1-w The doping concentration of the N-layer is 1×10⁻⁶. 19 cm -3 Up to 1×10 20 cm -3 Al E Ga 1-E The N layer is Mg-doped, and Al E Ga 1-E The doping concentration of the N-layer is 1×10⁻⁶. 19 cm -3 Up to 1×10 20 cm -3 Alternatively, the p-type aluminum-containing semiconductor layer comprises 2 to 15 GaN layers and 2 to 15 Al layers. E Ga 1-E N-layer; in the p-type aluminum-containing semiconductor layer, the GaN layer is Mg-doped, and the doping concentration of the GaN layer is 1×10⁻⁶. 19 cm -3 Up to 1×10 20 cm-3 Al E Ga 1-E The N layer is Mg-doped, and Al E Ga 1-E The doping concentration of the N-layer is 1×10⁻⁶. 19 cm -3 Up to 1×10 20 cm -3 .

[0010] Optionally, the n-type GaN layer is Si-doped, and the doping concentration of the n-type GaN layer is greater than or equal to 2 × 10⁻⁶. 18 cm -3 .

[0011] Optionally, the light-emitting diode further includes a p-type GaN layer and a p-type contact layer, wherein the p-type GaN layer and the p-type contact layer are sequentially stacked on the p-type aluminum-containing semiconductor layer.

[0012] Optionally, the light-emitting diode is used when the current density is less than or equal to 3A / cm². 2 Under these conditions, the external quantum efficiency is greater than or equal to 35%.

[0013] Secondly, embodiments of this disclosure provide a method for fabricating a light-emitting diode, the method comprising: growing an n-type GaN layer on a substrate; and growing a shallow well layer on the surface of the n-type GaN layer, the shallow well layer comprising alternatingly stacked In... y Ga 1-y An N-layer and multiple GaN layers, 0.01 < Y ​​< 0.1; a multi-quantum well layer is grown on the surface of the shallow well layer, the multi-quantum well layer comprising multiple alternating layers of In. z Ga 1-z An N-layer and multiple GaN layers, 0.2 < Z < 0.3; a p-type aluminum-containing semiconductor layer is grown on the surface of the multiple quantum well layers.

[0014] Optionally, the preparation method is carried out in a reaction chamber, the top of which is provided with a spray head. The sidewall of the spray head includes a first annular injection region, a second annular injection region, a third annular injection region, a fourth annular injection region, and a fifth annular injection region arranged sequentially from bottom to top in a vertical direction. Each of the first annular injection region, the second annular injection region, the third annular injection region, the fourth annular injection region, and the fifth annular injection region is provided with a plurality of spaced-apart gas injection holes. Growing an n-type GaN layer on the substrate includes: injecting ammonia gas into the reaction chamber from the first annular injection region, the third annular injection region, and the fifth annular injection region, and injecting ammonia gas from the second annular injection region... The fourth annular injection region injects MO source into the reaction chamber, and the flow rate ratio of the first annular injection region, the second annular injection region, the third annular injection region, the fourth annular injection region, and the fifth annular injection region is controlled to be 11.a:28.b:11.c:28.d:20.e, where a+b+c+d+e=20; The shallow well layer is grown on the surface of the n-type GaN layer, comprising: injecting ammonia gas into the reaction chamber from the first annular injection region, the third annular injection region, and the fifth annular injection region; injecting MO source into the reaction chamber from the second annular injection region and the fourth annular injection region; and controlling the flow rate ratio of the first annular injection region, the second annular injection region, the third annular injection region, the fourth annular injection region, and the fifth annular injection region to be 11.a:28.b:11.c:28.d:20.e, where a+b+c+d+e=20; The flow rate ratio of the first, third, fourth, and fifth annular injection regions is 21.a:18.b:19.c:19.d:21.e, where a+b+c+d+e=20. Growing a multi-quantum-well layer on the surface of the shallow well layer includes: injecting ammonia gas into the reaction chamber from the first, third, and fifth annular injection regions; injecting an MO source into the reaction chamber from the second and fourth annular injection regions; and controlling the flow rate ratio of the first, second, third, fourth, and fifth annular injection regions to 2. 1.a:18.b:19.c:19.d:21.e, a+b+c+d+e=20; Growing a p-type aluminum-containing semiconductor layer on the surface of the multi-quantum-well layer includes: injecting ammonia gas into the reaction chamber from the first annular injection region, the third annular injection region, and the fifth annular injection region; injecting an MO source into the reaction chamber from the second annular injection region and the fourth annular injection region; and controlling the flow rate ratio of the first annular injection region, the second annular injection region, the third annular injection region, the fourth annular injection region, and the fifth annular injection region to be 20.a:19.b:20.c:19.d:21.e, a+b+c+d+e=10.

[0015] The beneficial effects of the technical solutions provided in this disclosure include at least the following:

[0016] The light-emitting diode provided in this disclosure is based on an n-type GaN layer, and incorporates alternating In... y Ga 1-y A shallow well layer composed of N-layers and GaN-layers serves as a transition, followed by connections of In... z Ga 1-z A multi-quantum-well layer is formed by alternating N-layers and GaN-layers, and finally, a p-type aluminum-containing semiconductor layer is stacked on top of the multi-quantum-well layer. Among them, the In-type semiconductor layer stacked in the shallow well layer... y Ga 1-y The low y-value of N forms a narrower potential barrier with the GaN layer, enabling more efficient pre-aggregation and guidance of carriers to transition to the multi-quantum-well layer under extremely low current, thus reducing initial injection resistance. Secondly, the z-value of In in the multi-quantum-well layer is controlled between 0.2 and 0.3. z Ga 1-z The combination of the N-well layer and the GaN barrier layer creates a gradient match between the barrier height and the shallow well layer, allowing electrons and holes to enter the well region through shorter tunneling paths even at low concentrations, thus increasing the probability of radiative recombination. Furthermore, the p-type aluminum-containing semiconductor layer can adjust the conduction band barrier through Al composition, effectively preventing electron leakage into the p-type region. Simultaneously, the optimized valence band barrier of the p-type aluminum-containing semiconductor layer reduces the difficulty of hole injection, thereby decreasing non-radiative recombination.

[0017] Compared to related technologies, the light-emitting diode in this embodiment can inject charge carriers into multiple quantum wells with higher efficiency and distribute them uniformly under extremely low operating current, and the radiative recombination ratio can be effectively improved, thereby obtaining higher internal quantum efficiency. At the same time, the charge carrier transport path is shortened and the recombination rate is accelerated, and the response speed of the chip device is improved accordingly, solving the problems of low optical power and slow response under low current. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a light-emitting diode provided in an embodiment of this disclosure;

[0020] Figure 2 This is a flowchart of a method for fabricating a light-emitting diode according to an embodiment of this disclosure;

[0021] Figure 3 This is a schematic diagram of the structure of a reaction chamber provided in an embodiment of this disclosure.

[0022] The markings in the diagram are explained as follows:

[0023] 10. Substrate;

[0024] 20. 3D layer;

[0025] 30. Electron blocking layer;

[0026] 40. n-type GaN layer;

[0027] 51. First shallow well barrier layer; 52. Second shallow well barrier layer;

[0028] 60. Shallow trap layer;

[0029] 70. Multiple quantum well layers;

[0030] 81. GaN barrier layer; 82. Low-temperature GaN layer; 83. p-type aluminum-containing semiconductor layer; 84. p-type GaN layer; 85. p-type contact layer;

[0031] 90. Spray head; 91. First annular injection zone; 92. Second annular injection zone; 93. Third annular injection zone; 94. Fourth annular injection zone; 95. Fifth annular injection zone. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0033] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” “right,” “top,” and “bottom,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0034] Figure 1 This is a schematic diagram of the structure of a light-emitting diode provided in an embodiment of this disclosure. For example... Figure 1As shown, the light-emitting diode includes an n-type GaN layer 40, a shallow well layer 60, a multiple quantum well layer 70, and a p-type aluminum-containing semiconductor layer 83 stacked sequentially.

[0035] The shallow well layer 60 includes multiple In layers stacked alternately. y Ga 1-y N layers and multiple GaN layers, 0.01 < Y ​​< 0.1.

[0036] Among them, the multi-quantum well layer 70 includes multiple In layers stacked alternately. z Ga 1-z N layers and multiple GaN layers, 0.2 < Z < 0.3.

[0037] The light-emitting diode provided in this disclosure is based on an n-type GaN layer 40, and incorporates alternating In... y Ga 1-y A shallow well layer 60, consisting of N-layers and GaN-layers, serves as a transition layer, which is then connected to In... z Ga 1-z The multi-quantum well layer 70, formed by alternating N-layers and GaN layers, is finally stacked on top of the multi-quantum well layer 70 with a p-type aluminum-containing semiconductor layer 83. Among these, the In layers stacked in the shallow well layer 60... y Ga 1-y The low y-value of N forms a narrower potential barrier with the GaN layer, enabling more efficient pre-aggregation and guidance of carriers to transition to the multi-quantum-well layer 70 under extremely low current, thus reducing initial injection resistance. Secondly, the z-value of In in the multi-quantum-well layer 70 is controlled between 0.2 and 0.3. z Ga 1-z The combination of the N-well layer and the GaN barrier layer creates a gradient match between the barrier height and the shallow well layer 60, allowing electrons and holes to enter the well region through shorter tunneling paths even at low concentrations, thus increasing the probability of radiative recombination. Furthermore, the p-type aluminum-containing semiconductor layer 83 can adjust the conduction band barrier through Al composition, effectively preventing electron leakage into the p-type region. Simultaneously, the optimized valence band barrier of the p-type aluminum-containing semiconductor layer 83 reduces the difficulty of hole injection and decreases non-radiative recombination.

[0038] Compared to related technologies, the light-emitting diode in this embodiment can inject charge carriers into multiple quantum wells with higher efficiency and distribute them uniformly under extremely low operating current, and the radiative recombination ratio can be effectively improved, thereby obtaining higher internal quantum efficiency. At the same time, the charge carrier transport path is shortened and the recombination rate is accelerated, and the response speed of the chip device is improved accordingly, solving the problems of low optical power and slow response under low current.

[0039] Optionally, the shallow trap layer 60 includes 3 to 20 layers of In y Ga 1-y N-layer and 3 to 20 GaN layers.

[0040] In the shallow well layer 60, In y Ga 1-y The N layer is Si-doped, and In y Ga 1-y The doping concentration of the N-layer is 1×10⁻⁶. 17 cm -3 Up to 1×10 18 cm -3 .

[0041] The GaN layer is doped with Si, and the doping concentration of the GaN layer is 1.5 × 10⁻⁶. 17 cm -3 Up to 1×10 18 cm -3 .

[0042] In the above implementation, Si is doped into In y Ga 1-y Introducing a suitable amount of free electrons into the N-layer and GaN-layer, In y Ga 1-y The N-layer doping concentration is similar to or slightly lower than that of the GaN layer, which balances the electron supply capability. Under extremely low current, these extra electrons can supplement the carrier concentration, assisting electrons to pass more smoothly through the shallow well layer 60 into the multiple quantum wells, avoiding the problem of low injection efficiency caused by insufficient carriers, and increasing the proportion of electrons participating in radiative recombination in the active region.

[0043] At the same time, alternating layers of In y Ga 1-y The N-layer and GaN-layer can form a gradient potential barrier and potential well, while appropriate Si doping can slightly adjust the band positions of each layer, allowing In... y Ga 1-y The smoother band transition between the N-layer and the GaN-layer reduces carrier scattering and energy loss when passing through the interface, which helps carriers to transport more efficiently within the shallow well layer 60 and further creates favorable conditions for subsequent entry into the multi-quantum well layer 70.

[0044] Furthermore, the doping concentration is 1×10 17 cm -3 Up to 1×10 18 cm -3 The range ensures sufficient carrier replenishment while avoiding lattice distortion and defect increase caused by excessive doping. It reduces non-radiative recombination centers caused by defects, maintains the overall high-quality crystalline state of the shallow well layer 60, prevents leakage channels from forming, and ensures the stability and reliability of device performance.

[0045] For example, the shallow well layer 60 comprises 16 layers of In alternating layers. y Ga 1-y N-layer and 16-layer GaN.

[0046] For example, the thickness of the shallow well layer 60 is 20 nm to 150 nm.

[0047] Among them, In the shallow well layer 60 y Ga 1-y The thickness of the N layer is 10 to 30 angstroms, and the thickness of the GaN layer is 100 to 200 angstroms.

[0048] By controlling the thickness of the shallow well layer 60 within the above range, it avoids insufficient barrier modulation due to excessive thinness or carrier transport hysteresis due to excessive thickness, thus balancing low current injection efficiency and device response speed, while maintaining epitaxial layer stress balance and reducing defect risk.

[0049] Optionally, the multi-quantum-well layer 70 includes 3 to 10 layers of In z Ga 1-z N-layer and 3 to 10 GaN layers.

[0050] Among them, in the multi-quantum well layer 70, In z Ga 1-z The N-layer is undoped, the GaN-layer is Si-doped, and the doping concentration of the GaN-layer is 1×10⁻⁶. 17 cm -3 Up to 1×10 18 cm -3 .

[0051] In the above implementation, the In of the multiple quantum well layer 70 z Ga 1-z The N-layer is undoped, avoiding the scattering or non-radiative recombination centers introduced by doping of additional charge carriers. This ensures that electrons and holes can efficiently accumulate and recombine in the well layer under low current, maximizing the radiative recombination probability and enhancing the luminescence intensity.

[0052] Furthermore, the GaN barrier layer introduces an appropriate amount of free electrons through Si doping, forming a weak n-type conductive layer. On the one hand, the doping concentration is moderate, which will not destroy the quantum confinement effect of the well layer due to excessive carrier concentration; on the other hand, the doped electrons can help holes reduce scattering resistance when passing through the barrier layer, promote smoother hole injection into adjacent well layers, balance the distribution of electrons and holes in multiple quantum wells, and improve recombination uniformity.

[0053] Meanwhile, the alternating number of layers 3 to 10 in the multi-quantum well layer 70 can form a sufficient number of quantum well units to enhance the overall luminescence efficiency, while avoiding stress accumulation or interface defects caused by too many layers.

[0054] For example, the multi-quantum-well layer 70 includes eight layers of In alternating stacks. z Ga 1-z N-layer and 8-layer GaN.

[0055] For example, the thickness of the multiple quantum well layer 70 is 80 nm to 1500 nm.

[0056] Among them, in the multi-quantum well layer 70, In z Ga 1-z The thickness of the N layer is 10 to 30 angstroms, and the thickness of the GaN layer is 100 to 200 angstroms.

[0057] In some implementations, the p-type aluminum-containing semiconductor layer 83 includes multiple alternating layers of In... w Ga 1-w N layers and multiple Al E Ga 1-E For layer N, 0.0001 < W < 0.05, and 0.005 < E < 0.2.

[0058] Among them, In with low In content w Ga 1-w N-layer and Al with moderate Al composition E Ga 1-E The alternation of N layers forms a gradual potential barrier. The low In composition reduces interference with the valence band, while the moderate Al composition raises the conduction band barrier, effectively blocking electron leakage to the p-type region and reducing nonradiative recombination.

[0059] Meanwhile, the extremely low In content avoids the high defect and stress problems common in InGaN, ensuring the crystal quality of the epitaxial layer; the moderate Al content enhances the electron blocking ability while preventing lattice mismatch and stress accumulation caused by excessive Al content, maintaining structural stability, ensuring a good interface between the p-type layer and the multi-quantum well layer 70, thereby improving the overall luminescence performance and reliability of the device.

[0060] Optionally, the p-type aluminum-containing semiconductor layer 83 includes 2 to 15 layers of In. w Ga 1-w N layers and Al layers 2 to 15 E Ga 1-E N layers.

[0061] In p-type aluminum-containing semiconductor layer 83, In w Ga 1-w The N layer is Mg-doped, and In w Ga 1-w The doping concentration of the N-layer is 1×10⁻⁶. 19 cm -3 Up to 1×10 20 cm -3 .

[0062] Al E Ga 1-E The N layer is Mg-doped, and Al E Ga 1-E The doping concentration of the N-layer is 1×10⁻⁶.19 cm -3 Up to 1×10 20 cm -3 .

[0063] In the above implementation, high concentration of Mg doping in In w Ga 1-w N layer and Al E Ga 1-E A large number of holes are introduced into layer N, In w Ga 1-w The valence band structure of the N-layer, with its extremely low In content, is similar to that of GaN, allowing for smoother hole conduction; Al E Ga 1-E The N-layer uses an appropriate amount of Al composition to compensate for the high acceptor activation energy caused by the high Al composition through high Mg doping, making it easier for holes to be activated and injected into the multi-quantum well layer 70, improving hole injection efficiency and increasing the probability of electron-hole recombination in the active region.

[0064] Furthermore, the alternating stacked structure of p-type aluminum-containing semiconductor layers 83 forms a gradient potential barrier, In w Ga 1-w N-layer and Al E Ga 1-E The similar Mg doping concentration in the N layers ensures uniform distribution and transport of holes between layers.

[0065] Meanwhile, the p-type aluminum semiconductor layer 83 has an alternating number of layers from 2 to 15, which not only forms a sufficient number of functional layers to achieve efficient hole injection and electron blocking, but also avoids stress accumulation and defect increase caused by too many layers, maintains the overall crystal quality of the epitaxial layer, and ensures stable and efficient light emission of the device.

[0066] For example, the thickness of the p-type aluminum-containing semiconductor layer 83 is 20 nm to 150 nm.

[0067] For example, in the p-type aluminum-containing semiconductor layer 83, In w Ga 1-w The thickness of the N layer is 1 nm to 10 nm, Al E Ga 1-E The thickness of the N layer ranges from 1 nm to 10 nm.

[0068] In some other implementations, the p-type aluminum-containing semiconductor layer 83 comprises multiple alternating GaN layers and multiple Al layers. E Ga 1-E N layer, 0.005<E<0.2.

[0069] Controlling AI E Ga 1-EWith the Al composition content within the aforementioned range, the high conduction band barrier effectively blocks electron leakage to the p-type region, reducing nonradiative recombination of electrons in the non-active region. Simultaneously, the valence band barrier, after being modulated by Mg doping, reduces hole injection resistance, facilitating efficient hole transport to the multi-quantum-well layer 70. The GaN layer, acting as a buffer between barriers, provides a stable carrier transport path, interacting with Al... E Ga 1-E N-layer collaboration enhances carrier confinement capability.

[0070] Compared to In containing In components w Ga 1-w N-layer, pure GaN layer and Al E Ga 1-E The alternating N-layer structure avoids the lattice mismatch and stress concentration problems caused by the high In content of InGaN, reduces the defect density in the epitaxial layer, reduces non-radiative recombination centers, ensures the crystal quality of the p-type layer, and improves the stability of hole injection.

[0071] Optionally, the p-type aluminum-containing semiconductor layer 83 includes 2 to 15 GaN layers and 2 to 15 Al layers. E Ga 1-E N layers.

[0072] In the p-type aluminum-containing semiconductor layer 83, the GaN layer is Mg-doped, and the doping concentration of the GaN layer is 1×10⁻⁶. 19 cm -3 Up to 1×10 20 cm -3 .

[0073] Al E Ga 1-E The N layer is Mg-doped, and Al E Ga 1-E The doping concentration of the N-layer is 1×10⁻⁶. 19 cm -3 Up to 1×10 20 cm -3 .

[0074] High concentrations of Mg are doped in the GaN and Al layers. E Ga 1-E A large number of holes are introduced into the N-layer. As a common p-type material, GaN can stably conduct holes; Al E Ga 1-E The N-layer compensates for the high acceptor activation energy caused by the high Al composition by high Mg doping, activating more holes and making it easier for holes to be injected into the multi-quantum well layer 70, thereby increasing the probability of electron-hole recombination and enhancing luminescence efficiency.

[0075] Furthermore, Al E Ga 1-EWhen the Al content in the N-layer is controlled within the aforementioned range, a high conduction band barrier can be formed, effectively preventing electron leakage to the p-type region, reducing non-radiative recombination, and ensuring that more charge carriers participate in radiative recombination luminescence in the multi-quantum-well layer 70. The GaN layer, as a buffer layer, provides a stable carrier transport path and interacts with Al... E Ga 1-E N-layer collaboration enhances carrier confinement capability.

[0076] Meanwhile, the p-type aluminum semiconductor layer 83 is designed with alternating layers of 2 to 15 layers, which not only forms a sufficient number of functional layers to achieve efficient hole injection and electron blocking, but also avoids stress accumulation and defect increase due to excessive layers, maintains the overall crystal quality of the epitaxial layer, and ensures stable and efficient light emission of the device.

[0077] For example, the thickness of the p-type aluminum-containing semiconductor layer 83 is 20 nm to 150 nm.

[0078] For example, in the p-type aluminum-containing semiconductor layer 83, the GaN layer has a thickness of 1 nm to 10 nm, and the Al... E Ga 1-E The thickness of the N layer ranges from 1 nm to 10 nm.

[0079] Optionally, the n-type GaN layer 40 is Si-doped, and the doping concentration of the n-type GaN layer 40 is greater than or equal to 2 × 10⁻⁶. 18 cm -3 .

[0080] High-concentration Si doping introduces a large number of free electrons into the GaN valence band, providing a sufficient electron source for the subsequent multiple quantum well layers. At extremely low current densities, the high electron concentration can effectively compensate for insufficient carrier injection, ensuring that the quantum well layers have enough electrons to participate in radiative recombination and avoiding a decrease in luminescence efficiency due to electron shortage.

[0081] Furthermore, high doping concentration can reduce the resistance of the n-type GaN layer 40, reduce ohmic losses during device operation, allow current to be injected into the active region more smoothly, reduce Joule heat generation, improve device heat dissipation performance and reliability, and accelerate chip response speed.

[0082] For example, the thickness of the n-type GaN layer 40 is 1000 nm to 2500 nm.

[0083] For example, the n-type GaN layer 40 is a single-layer Si-doped non-gradient GaN structure with a Si doping concentration range of 5 × 10⁻⁶. 18 cm -3 Up to 9×10 19 cm -3 .

[0084] For example, the n-type GaN layer 40 is a single-layer Si-doped graded GaN structure. The Si doping concentration can be gradually changed from low concentration to high concentration or from low concentration to high concentration and then back to low concentration. The gradual change can be linear or nonlinear.

[0085] The Si doping concentration ranges from 2.5 × 10⁻⁶ to 2.5 × 10⁻⁶. 18 cm -3 Up to 9×10 19 cm -3 .

[0086] For example, the n-type GaN layer 40 is composed of multiple GaN structures with different Si doping concentrations.

[0087] For example, the n-type GaN layer 40 includes three Si-doped GaN layers.

[0088] The Si doping concentration range of the first GaN layer is 2×10⁻⁶. 18 cm -3 Up to 2×10 19 cm -3 .

[0089] The Si doping concentration range of the second GaN layer is 5 × 10⁻⁶. 18 cm -3 Up to 5×10 19 cm -3 .

[0090] The Si doping concentration range of the third GaN layer is 5 × 10⁻⁶. 17 cm -3 Up to 1×10 19 cm -3 .

[0091] The thickness of the second GaN layer is greater than the sum of the thicknesses of the first and third GaN layers.

[0092] In the above implementation, the second GaN layer, with the highest doping concentration and the largest thickness, serves as the main electron supply layer, efficiently providing a large number of free electrons to ensure sufficient charge carriers in the quantum well under low current. The first and third GaN layers form a gradient buffer through appropriate Si doping concentration, reducing barrier impact during electron injection and optimizing the transport path. Simultaneously, the large thickness of the second GaN layer extends the high-concentration electron supply region, stably maintaining electron supply while avoiding lattice stress concentration caused by localized high doping.

[0093] Optionally, such as Figure 1 As shown, the light-emitting diode also includes a p-type GaN layer 84 and a p-type contact layer 85, which are sequentially stacked on the p-type aluminum-containing semiconductor layer 83.

[0094] For example, the p-type GaN layer 84 can be a high-temperature grown GaN layer, and the high-temperature grown GaN layer is Mg-doped, with a Mg doping concentration of 2 × 10⁻⁶. 19 cm -3 Up to 2×10 20 cm -3 .

[0095] The p-type GaN layer 84 employs a Mg-doped structure grown at high temperatures. This high-temperature growth process enhances the activation efficiency of the Mg dopant, allowing more Mg acceptors to form effective hole sources, increasing hole concentration, and strengthening hole injection capability. The high doping concentration ensures good ohmic contact between the p-type GaN layer 84 and the upper p-type contact layer 85, reducing contact resistance, decreasing voltage loss and Joule heat during device operation, and improving luminous efficiency and reliability. Simultaneously, as an intermediate layer for hole transport, this layer effectively adjusts the bandgap matching with the p-type aluminum semiconductor layer 83, optimizing the uniformity of hole distribution in the p-type region, allowing more holes to be injected into the multi-quantum well layer 70 to participate in radiative recombination, further improving internal quantum efficiency and luminous performance at low current densities.

[0096] As an example, the thickness of the p-type GaN layer 84 ranges from 20 nm to 100 nm.

[0097] For example, the p-type contact layer 85 can be a Mg-doped GaN layer, and the Mg doping concentration is 2 × 10⁻⁶. 19 cm -3 Up to 2×10 20 cm -3 .

[0098] Among them, high-concentration Mg doping activates a large number of holes, reduces the contact resistance between the p-type contact layer 85 and the electrode, and improves the hole injection efficiency; the GaN material has a high lattice matching degree with the epitaxial layer, and the interface stress is small, which reduces non-radiative recombination caused by defects.

[0099] As an example, the thickness of the p-type contact layer 85 ranges from 1 nm to 100 nm.

[0100] Optionally, such as Figure 1 As shown, the light-emitting diode also includes a substrate 10, a buffer layer, a 3D layer 20, and an electron blocking layer 30. The buffer layer, the 3D layer 20, and the electron blocking layer 30 are stacked sequentially on the substrate 10, and the n-type GaN layer 40 is located on the electron blocking layer 30.

[0101] For example, the substrate can be a patterned sapphire substrate or a planar sapphire substrate.

[0102] The substrate thickness ranges from 1000 μm to 1400 μm. The substrate diameter is 150 ± 0.1 mm. The substrate BOW value is -10 μm to 0 μm. The substrate TTV value is ≤10 μm.

[0103] For example, the substrate is either flat-edge or notch-type.

[0104] For example, when the substrate is a patterned substrate, the bottom width of the pattern ranges from 1.0 to 3.0 ± 0.1 μm, the height of the pattern ranges from 0.4 to 1.9 ± 0.1 μm, and the spacing between the patterns ranges from 0.1 to 0.4 ± 0.1 μm.

[0105] For example, the buffer layer may be an AlN layer with a thickness of 10 nm to 30 nm.

[0106] For example, the buffer layer may be a GaN layer with a thickness of 10 nm to 50 nm.

[0107] Optionally, the 3D layer 20 includes a three-dimensional GaN layer, a two-dimensional GaN layer, and a high-temperature GaN layer stacked sequentially.

[0108] The thickness of the 3D layer 20 is 2μm to 4μm.

[0109] For example, the two-dimensional GaN layer is an intrinsic GaN structure without Si doping.

[0110] For example, the two-dimensional GaN layer is a Si-doped GaN structure, and the Si doping concentration ranges from 1×10⁻⁶. 18 cm -3 Up to 3×10 19 cm -3 .

[0111] For example, the high-temperature GaN layer is an intrinsic GaN structure without Si doping.

[0112] For example, the high-temperature GaN layer is a Si-doped GaN structure, and the Si doping concentration ranges from 1×10⁻⁶. 18 cm -3 Up to 3×10 19 cm -3 .

[0113] Optionally, the electron blocking layer 30 is an AlGaN layer. The high Al content AlGaN layer, as the electron blocking layer 30 of the overall epitaxial structure, can reduce the electron spillover effect.

[0114] The AlGaN layer can be Al X Ga 1-X N layer, 0.005 < X < 0.1. The thickness of the AlGaN layer is 10 nm to 200 nm.

[0115] Optionally, such as Figure 1 As shown, the light-emitting diode also includes: a first shallow well barrier layer 51 and a second shallow well barrier layer 52.

[0116] The first shallow well barrier layer 51 is located between the n-type GaN layer 40 and the shallow well layer 60, and the second shallow well barrier layer 52 is located between the shallow well layer 60 and the multi-quantum well layer 70.

[0117] In the above implementation, both the first shallow well barrier layer 51 and the second shallow well barrier layer 52 are stress relief layers, which can alleviate the stress in the epitaxial layer.

[0118] For example, the thickness of the first shallow well barrier layer 51 is 20 nm to 300 nm.

[0119] For example, the first shallow well barrier layer 51 is a Si-doped GaN structure, and the Si doping concentration range is 1×10⁻⁶. 17 cm -3 Up to 1×10 19 cm -3 .

[0120] For example, the first shallow well barrier layer 51 is a multilayer Si-doped GaN structure, with the Si doping concentration in each layer ranging from 1×10⁻⁶. 17 cm -3 Up to 1×10 19 cm -3 .

[0121] For example, the first shallow well barrier layer 51 is an intrinsic GaN structure without Si doping.

[0122] For example, the first shallow well barrier layer 51 is a low In composition InGaN layer, with an In composition lower than that in the shallow well layer 60, and the Si doping concentration range is 1×10⁻⁶. 17 cm -3 Up to 5×10 18 cm -3 .

[0123] For example, the thickness of the second shallow well barrier layer 52 is 50 nm to 300 nm.

[0124] For example, the second shallow well barrier layer 52 is a Si-doped GaN structure, and the Si doping concentration range is 1×10⁻⁶. 17 cm -3 Up to 5×10 18 cm -3 .

[0125] For example, the second shallow well barrier layer 52 is a multilayer Si-doped GaN structure, with the Si doping concentration in each layer ranging from 1×10⁻⁶. 17 cm-3 Up to 5×10 18 cm -3 .

[0126] For example, the second shallow well barrier layer 52 is an intrinsic GaN structure without Si doping.

[0127] Optionally, such as Figure 1 As shown, the light-emitting diode further includes a GaN barrier layer 81 and a low-temperature GaN layer 82. The GaN barrier layer 81 and the low-temperature GaN layer 82 are sequentially stacked on the multi-quantum-well layer 70, and the p-type aluminum-containing semiconductor layer 83 is stacked on the low-temperature GaN layer 82.

[0128] For example, the thickness of the GaN barrier layer 81 is 2 nm to 20 nm.

[0129] Example site selection: GaN barrier layer 81 is Al K Ga 1-K For layer N, 0.005 < K < 0.1.

[0130] In the example site selection, the GaN barrier layer 81 is a periodic structure of AlN / GaN, wherein the Al component content is 0.5% to 10% and the number of periods is 2 to 10.

[0131] For example, the thickness of the low-temperature GaN layer 82 is 20 nm to 100 nm.

[0132] For example, the low-temperature GaN layer 82 is Mg-doped, and the Mg doping concentration is 1×10⁻⁶. 19 cm -3 Up to 5×10 20 cm -3 .

[0133] The data comparison between the light-emitting diodes provided in this embodiment and those in related technologies is shown in Table 1 below.

[0134] Table 1

[0135]

[0136] As shown in Table 1, the light-emitting diode provided in this embodiment has significantly higher light power than the light-emitting diodes in related technologies under operating currents of 5μA and 10μA.

[0137] In this embodiment of the disclosure, the light-emitting diode is operating at a current density less than or equal to 3A / cm². 2Under certain operating conditions, the external quantum efficiency is greater than or equal to 35%. It is evident that with an external quantum efficiency ≥35% at low current density, the LED can achieve high-efficiency light emission with low energy consumption, significantly reducing power consumption and heat generation, and improving energy utilization. This makes it suitable for power-sensitive applications such as portable devices and micro-displays, and also enhances the stability of light emission under low current conditions.

[0138] Figure 2 This is a flowchart illustrating a method for fabricating a light-emitting diode (LED) according to an embodiment of this disclosure. This method is used to fabricate... Figure 1 The light-emitting diode shown. (As shown in the image) Figure 2 As shown, the preparation method includes:

[0139] S11: An n-type GaN layer is grown on the substrate.

[0140] S12: A shallow well layer is grown on the surface of an n-type GaN layer.

[0141] The shallow well layer comprises multiple In layers stacked alternately. y Ga 1-y N layers and multiple GaN layers, 0.01 < Y ​​< 0.1.

[0142] S13: Grow a multi-quantum-well layer on the surface of a shallow-well layer.

[0143] Among them, the multi-quantum well layer includes multiple In alternating stacks. z Ga 1-z N layers and multiple GaN layers, 0.2 < Z < 0.3.

[0144] S14: Grow a p-type aluminum-containing semiconductor layer on the surface of a multi-quantum-well layer.

[0145] In this embodiment, the fabrication method of the light-emitting diode is carried out within a reaction chamber. Epitaxial growth uses TMGa, TEGa, and TMIn as group III MO precursor reactants, NH3 as group V precursor reactants, SiH4 and CP2Mg as n-type and p-type dopants, respectively, and N2 and H2 as carrier gases / atmospheres.

[0146] Figure 3 This is a schematic diagram of the structure of a reaction chamber provided in an embodiment of this disclosure. Figure 3 As shown, the top of the reaction chamber is provided with a spray head 90. The sidewall of the spray head 90 includes a first annular injection zone 91, a second annular injection zone 92, a third annular injection zone 93, a fourth annular injection zone 94 and a fifth annular injection zone 95 arranged sequentially from bottom to top in the vertical direction. Each of the first annular injection zone 91, the second annular injection zone 92, the third annular injection zone 93, the fourth annular injection zone 94 and the fifth annular injection zone 95 is provided with a plurality of spaced airflow injection holes.

[0147] In the above implementation, the five-layer annular injection region allows for more precise airflow distribution control in the vertical direction. Different annular injection regions can independently adjust their airflow rate and ratio, precisely delivering reactive gases such as ammonia and MO source according to the growth requirements of each epitaxial layer. This results in a more accurate matching of the growth environment for each layer, improving crystal quality and performance.

[0148] Furthermore, the top-spraying, five-layer annular injection zone allows for a more uniform distribution of reactive gases within the reaction chamber. Each gas layer is injected through spaced-apart injection holes, creating a uniform gas flow field. This prevents excessively high or low local gas concentrations, ensuring uniform epitaxial layer growth across all areas of the substrate, reducing performance differences caused by uneven growth, and improving overall device performance and yield.

[0149] Step S11 may include: injecting ammonia gas into the reaction chamber from the first annular injection zone, the third annular injection zone, and the fifth annular injection zone; injecting an MO source into the reaction chamber from the second annular injection zone and the fourth annular injection zone; and controlling the flow rate ratio of the first annular injection zone, the second annular injection zone, the third annular injection zone, the fourth annular injection zone, and the fifth annular injection zone to be 11.a:28.b:11.c:28.d:20.e, where a+b+c+d+e=20.

[0150] The flow rate ratio of the n-type GaN layer is 11.a:28.b:11.c:28.d:20.e, where a+b+c+d+e=20. This ratio ensures that the gas flow distribution precisely matches the growth requirements of the n-type GaN layer. The higher proportion of MO source in the second and fourth annular injection regions provides sufficient metal source for GaN growth, while ammonia gas is injected into the first, third, and fifth annular injection regions to provide nitrogen source, ensuring stable synthesis of gallium nitride. The overall proportions are well-coordinated, resulting in high crystal quality of the n-type GaN layer, laying a solid foundation for subsequent layer growth. Furthermore, the suitable flow rate distribution facilitates efficient electron injection, meeting the high electron concentration requirement of the n-type layer.

[0151] It should be noted that when ammonia is injected into the reaction chamber from the first, third, and fifth annular injection zones, a carrier gas is also injected along with the ammonia. The carrier gas may include at least one of nitrogen and hydrogen.

[0152] When the MO source is injected into the reaction chamber from the second and fourth annular injection regions, a carrier gas is also injected along with the MO source. The MO source may include dopants such as TMGa, TEGa, TMIn, TMAl, TMIn, SiH4, and CP2Mg, and the carrier gas may include at least one of nitrogen and hydrogen.

[0153] Step S12 may include: injecting ammonia gas into the reaction chamber from the first annular injection zone, the third annular injection zone, and the fifth annular injection zone; injecting an MO source into the reaction chamber from the second annular injection zone and the fourth annular injection zone; and controlling the flow rate ratio of the first annular injection zone, the second annular injection zone, the third annular injection zone, the fourth annular injection zone, and the fifth annular injection zone to be 21.a:18.b:19.c:19.d:21.e, where a+b+c+d+e=20.

[0154] The flow rate ratio of the shallow well layer is 21.a:18.b:19.c:19.d:21.e, where a+b+c+d+e=20. This ratio optimizes the growth environment of the shallow well layer. Compared to n-type GaN layers, fine-tuning the ratio of MO source and ammonia helps to form a suitable In layer. y Ga 1-y The structure alternates between N-layers and GaN-layers. A suitable flux ratio allows for uniform growth of each sublayer in the shallow well layer, forming a good barrier and well transition, which facilitates carrier transport to the multi-quantum well layer under low current and improves carrier injection efficiency.

[0155] Step S13 may include: injecting ammonia gas into the reaction chamber from the first annular injection zone, the third annular injection zone, and the fifth annular injection zone; injecting MO source into the reaction chamber from the second annular injection zone and the fourth annular injection zone; and controlling the flow rate ratio of the first annular injection zone, the second annular injection zone, the third annular injection zone, the fourth annular injection zone, and the fifth annular injection zone to be 21.a:18.b:19.c:19.d:21.e, where a+b+c+d+e=20.

[0156] The same flux ratio between the multi-quantum-well layer and the shallow-well layer ensures the consistency and stability of the multi-quantum-well layer growth. This ratio enables In... z Ga 1-z The alternating growth of N-layers and GaN-layers forms an ideal quantum well structure. A suitable ratio of MO source to ammonia allows for precise shaping of the well and barrier layers, facilitating efficient recombination of electrons and holes within the well layer and improving luminescence efficiency.

[0157] Step S14 may include: injecting ammonia gas into the reaction chamber from the first annular injection zone, the third annular injection zone, and the fifth annular injection zone; injecting an MO source into the reaction chamber from the second annular injection zone and the fourth annular injection zone; and controlling the flow rate ratio of the first annular injection zone, the second annular injection zone, the third annular injection zone, the fourth annular injection zone, and the fifth annular injection zone to be 20.a:19.b:20.c:19.d:21.e, where a+b+c+d+e=10.

[0158] The flow rate ratio for the p-type aluminum-containing semiconductor layer is 20.a:19.b:20.c:19.d:21.e, where a+b+c+d+e=10, adjusted to suit the growth characteristics of the p-type aluminum-containing semiconductor layer. Compared to the previous layers, the change in flow rate ratio affects the Al... E Ga 1-E N layers and In w Ga 1-w The N-layer (or GaN layer) growth environment is more suitable. This ratio ensures uniform growth of the aluminum-containing layer and alternating layers. The resulting p-type aluminum-containing semiconductor layer can effectively block electron leakage while facilitating hole injection, thereby increasing the hole concentration and injection efficiency of the p-type layer and meeting the functional requirements of the p-type layer.

[0159] The following steps may also be included before step S11:

[0160] The first step involves transferring the substrate into the reaction chamber and placing it in the substrate position on the graphite disk. The substrate is then preheated in the MOCVD furnace at a temperature of 1100°C to 1200°C in a pure hydrogen atmosphere.

[0161] For example, the substrate can be a patterned sapphire substrate or a planar sapphire substrate.

[0162] The substrate thickness ranges from 1000 μm to 1400 μm. The substrate diameter is 150 ± 0.1 mm. The substrate BOW value is -10 μm to 0 μm. The substrate TTV value is ≤10 μm.

[0163] For example, the substrate is either flat-edge or notch-type.

[0164] For example, when the substrate is a patterned substrate, the bottom width of the pattern ranges from 1.0 to 3.0 ± 0.1 μm, the height of the pattern ranges from 0.4 to 1.9 ± 0.1 μm, and the spacing between the patterns ranges from 0.1 to 0.4 ± 0.1 μm.

[0165] The second step involves using PVD to pre-sputter the AlN layer outside the MOCVD furnace, or growing the AlN layer directly inside the MOCVD furnace, or growing the GaN layer directly to form a buffer layer on the substrate.

[0166] The third step involves sequentially growing a three-dimensional GaN layer, a two-dimensional GaN layer, and a high-temperature GaN layer on the buffer layer to obtain the 3D layer.

[0167] For example, the two-dimensional GaN layer is an intrinsic GaN structure without Si doping.

[0168] For example, the two-dimensional GaN layer is a Si-doped GaN structure, and the Si doping concentration ranges from 1×10⁻⁶. 18 cm -3 Up to 3×10 19 cm-3 .

[0169] For example, the high-temperature GaN layer is an intrinsic GaN structure without Si doping.

[0170] For example, the high-temperature GaN layer is a Si-doped GaN structure, and the Si doping concentration ranges from 1×10⁻⁶. 18 cm -3 Up to 3×10 19 cm -3 .

[0171] The fourth step is to grow an electron blocking layer on the 3D layer.

[0172] For example, the electron blocking layer is an AlGaN layer. The AlGaN layer with a high Al content serves as the electron blocking layer of the overall epitaxial structure, which can reduce the electron spillover effect.

[0173] The AlGaN layer can be Al X Ga 1-X N layer, 0.005 < X < 0.1. The thickness of the AlGaN layer is 10 nm to 200 nm.

[0174] For example, when growing an AlGaN layer, the flow rate ratio of the first annular injection region, the second annular injection region, the third annular injection region, the fourth annular injection region and the fifth annular injection region can be controlled to be 11.a:28.b:11.c:28.d:20.e, where a+b+c+d+e=20.

[0175] The above ratio, through high MO source flow (approximately 56% in the second and fourth ring injection regions) and balanced ammonia distribution (approximately 42% in the first, third, and fifth ring injection regions), prioritizes ensuring the crystal quality and Al composition uniformity of AlGaN materials, making it suitable for scenarios requiring high electron blocking capability and reducing electron leakage to the p-type region.

[0176] For example, when growing an AlGaN layer, the flow rate ratio of the first annular injection region, the second annular injection region, the third annular injection region, the fourth annular injection region and the fifth annular injection region can be controlled to be 20.a:19.b:20.c:19.d:21.e, where a+b+c+d+e=10.

[0177] The above-mentioned proportions enhance ammonia injection (approximately 61% in the first, third, and fifth annular injection regions), reduce the proportion of MO source, decrease carbon impurity incorporation, and improve p-type doping efficiency.

[0178] Between steps S11 and S12, the following may also be included: growing a first shallow well barrier layer on the surface of the n-type GaN layer.

[0179] For example, the thickness of the first shallow well barrier layer is 20 nm to 300 nm.

[0180] For example, the first shallow well barrier layer is a Si-doped GaN structure, and the Si doping concentration ranges from 1×10⁻⁶. 17 cm -3 Up to 1×10 19 cm -3 .

[0181] For example, the first shallow well barrier layer is a multilayer Si-doped GaN structure, with the Si doping concentration in each layer ranging from 1×10⁻⁶. 17 cm -3 Up to 1×10 19 cm -3 .

[0182] For example, the first shallow well barrier layer is an intrinsic GaN structure without Si doping.

[0183] For example, the first shallow well barrier layer is a low-In-content InGaN layer, where the In content is lower than that in the shallow well layer, and the Si doping concentration range is 1×10⁻⁶. 17 cm -3 Up to 5×10 18 cm -3 .

[0184] When growing the first shallow well barrier layer, the flow rate ratio of the first annular injection region, the second annular injection region, the third annular injection region, the fourth annular injection region and the fifth annular injection region can be controlled to be 21.a:18.b:19.c:19.d:21.e, where a+b+c+d+e=20.

[0185] Between steps S12 and S13, a second shallow well barrier layer may also be grown on the surface of the shallow well layer.

[0186] For example, the thickness of the second shallow well barrier layer is 50 nm to 300 nm.

[0187] For example, the second shallow well barrier layer is a Si-doped GaN structure, and the Si doping concentration ranges from 1×10⁻⁶. 17 cm -3 Up to 5×10 18 cm -3 .

[0188] For example, the second shallow well barrier layer is a multilayer Si-doped GaN structure, with the Si doping concentration in each layer ranging from 1×10⁻⁶. 17 cm -3 Up to 5×10 18 cm -3 .

[0189] For example, the second shallow well barrier layer is an intrinsic GaN structure without Si doping.

[0190] When growing the second shallow well barrier layer, the flow rate ratio of the first annular injection region, the second annular injection region, the third annular injection region, the fourth annular injection region and the fifth annular injection region can be controlled to be 21.a:18.b:19.c:19.d:21.e, where a+b+c+d+e=20.

[0191] Between steps S13 and S14, the process may further include: sequentially growing a GaN barrier layer and a low-temperature GaN layer on the multi-quantum well layer.

[0192] For example, the thickness of the GaN barrier layer is 2 nm to 20 nm.

[0193] Example site selection: GaN barrier layer is Al K Ga 1-K For layer N, 0.005 < K < 0.1.

[0194] In the example site selection, the GaN barrier layer is a periodic structure of AlN / GaN, wherein the Al component content is 0.5% to 10% and the number of periods is 2 to 10.

[0195] When growing the GaN barrier layer, the flow rate ratio of the first, second, third, fourth, and fifth annular injection regions can be controlled to be 19.a:26.b:16.c:26.d:12.e, where a+b+c+d+e=10.

[0196] For example, the thickness of the low-temperature GaN layer is 20 nm to 100 nm.

[0197] For example, the low-temperature GaN layer is Mg-doped, and the Mg doping concentration is 1×10⁻⁶. 19 cm -3 Up to 5×10 20 cm -3 .

[0198] When growing a low-temperature GaN layer, the flow rate ratio of the first, second, third, fourth, and fifth annular injection regions can be controlled to be 12.a:30.b:12.c:30.d:14.e, where a+b+c+d+e=20.

[0199] Step S14 is followed by: sequentially growing a p-type GaN layer and a p-type contact layer on the p-type aluminum-containing semiconductor layer.

[0200] For example, the p-type GaN layer can be a GaN layer grown at high temperature, and the high-temperature grown GaN layer is Mg-doped, with a Mg doping concentration of 2 × 10⁻⁶.19 cm -3 Up to 2×10 20 cm -3 .

[0201] As an example, the thickness of the p-type GaN layer ranges from 20 nm to 100 nm.

[0202] For example, the p-type contact layer can be a Mg-doped GaN layer, and the Mg doping concentration is 2 × 10⁻⁶. 19 cm -3 Up to 2×10 20 cm -3 .

[0203] As an example, the thickness of the p-type contact layer ranges from 1 nm to 100 nm.

[0204] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A light-emitting diode, characterized in that, The light-emitting diode is suitable for current densities less than or equal to 3A / cm². 2 The operating conditions are such that the external quantum efficiency of the light-emitting diode is greater than or equal to 35%, and the light-emitting diode includes an n-type GaN layer (40), a shallow well layer (60), a multi-quantum well layer (70) and a p-type aluminum-containing semiconductor layer (83) stacked sequentially. The n-type GaN layer (40) comprises a first GaN layer, a second GaN layer, and a third GaN layer stacked sequentially and doped with Si. The Si doping concentration of the first GaN layer is in the range of 2 × 10⁻⁶. 18 cm -3 Up to 2×10 19 cm -3 The Si doping concentration range of the second GaN layer is 5 × 10⁻⁶. 18 cm -3 Up to 5×10 19 cm -3 The Si doping concentration range of the third GaN layer is 5 × 10⁻⁶. 17 cm -3 Up to 1×10 19 cm -3 The thickness of the second GaN layer is greater than the sum of the thicknesses of the first GaN layer and the third GaN layer; The shallow well layer (60) comprises multiple alternating layers of In y Ga 1-y N layers and multiple GaN layers, 0.01 < Y ​​< 0.1, in the shallow well layer (60), In y Ga 1-y The N layer is Si-doped, and In y Ga 1-y The doping concentration of the N-layer is 1×10⁻⁶. 17 cm -3 Up to 1×10 18 cm -3 The GaN layer is Si-doped, and the doping concentration of the GaN layer is 1.5 × 10⁻⁶. 17 cm -3 Up to 1×10 18 cm -3 ; The multi-quantum-well layer (70) comprises multiple In layers stacked alternately. z Ga 1-z The N-layer and multiple GaN layers, 0.2 < Z < 0.3, wherein in the multiple quantum well layer (70), the GaN layer is Si-doped and the doping concentration of the GaN layer is 1 × 10⁻⁶. 17 cm -3 Up to 1×10 18 cm -3 In the multi-quantum well layer (70), In z Ga 1-z The N-layer is undoped; The p-type aluminum-containing semiconductor layer (83) comprises multiple alternating GaN layers and multiple Al layers. E Ga 1-E In the N-layer, 0.005 < E < 0.2, in the p-type aluminum-containing semiconductor layer (83), the GaN layer is Mg-doped, and the doping concentration of the GaN layer is 1 × 10⁻⁶. 19 cm -3 Up to 1×10 20 cm -3 Al E Ga 1-E The N layer is Mg-doped, and Al E Ga 1-E The doping concentration of the N-layer is 1×10⁻⁶. 19 cm -3 Up to 1×10 20 cm -3 .

2. The light-emitting diode according to claim 1, characterized in that, The shallow well layer (60) comprises 3 to 20 layers of In y Ga 1-y N-layer and 3 to 20 GaN layers.

3. The light-emitting diode according to claim 1, characterized in that, The multi-quantum well layer (70) includes 3 to 10 layers of In z Ga 1-z N-layers and 3 to 10 GaN layers.

4. The light-emitting diode according to claim 1, characterized in that, The p-type aluminum-containing semiconductor layer (83) includes 2 to 15 GaN layers and 2 to 15 Al layers. E Ga 1-E N layers.

5. The light-emitting diode according to any one of claims 1 to 4, characterized in that, The n-type GaN layer (40) is Si-doped, and the doping concentration of the n-type GaN layer (40) is greater than or equal to 2 × 10⁻⁶. 18 cm -3 .

6. The light-emitting diode according to any one of claims 1 to 4, characterized in that, The light-emitting diode further includes a p-type GaN layer (84) and a p-type contact layer (85), wherein the p-type GaN layer (84) and the p-type contact layer (85) are sequentially stacked on the p-type aluminum-containing semiconductor layer (83).

7. A method for fabricating a light-emitting diode, characterized in that, The preparation method includes: An n-type GaN layer (40) is grown on a substrate (10). The n-type GaN layer (40) comprises a first GaN layer, a second GaN layer, and a third GaN layer that are sequentially stacked and doped with Si. The Si doping concentration of the first GaN layer is in the range of 2 × 10⁻⁶. 18 cm -3 Up to 2×10 19 cm -3 The Si doping concentration range of the second GaN layer is 5 × 10⁻⁶. 18 cm -3 Up to 5×10 19 cm -3 The Si doping concentration range of the third GaN layer is 5 × 10⁻⁶. 17 cm -3 Up to 1×10 19 cm -3 The thickness of the second GaN layer is greater than the sum of the thicknesses of the first GaN layer and the third GaN layer; A shallow well layer (60) is grown on the surface of the n-type GaN layer (40), the shallow well layer (60) comprising alternating layers of In y Ga 1-y N layers and multiple GaN layers, 0.01 < Y ​​< 0.1, in the shallow well layer (60), In y Ga 1-y The N layer is Si-doped, and In y Ga 1-y The doping concentration of the N-layer is 1×10⁻⁶. 17 cm -3 Up to 1×10 18 cm -3 The GaN layer is Si-doped, and the doping concentration of the GaN layer is 1.5 × 10⁻⁶. 17 cm -3 Up to 1×10 18 cm -3 ; A multi-quantum well layer (70) is grown on the surface of the shallow well layer (60), the multi-quantum well layer (70) comprising alternating layers of multiple In z Ga 1-z The N-layer and multiple GaN layers, 0.2 < Z < 0.3, wherein in the multiple quantum well layer (70), the GaN layer is Si-doped and the doping concentration of the GaN layer is 1 × 10⁻⁶. 17 cm -3 Up to 1×10 18 cm -3 In the multi-quantum well layer (70), In z Ga 1-z The N-layer is undoped; A p-type aluminum-containing semiconductor layer (83) is grown on the surface of the multi-quantum-well layer (70); the p-type aluminum-containing semiconductor layer (83) comprises multiple GaN layers and multiple Al layers stacked alternately. E Ga 1-E In the N-layer, 0.005 < E < 0.2, in the p-type aluminum-containing semiconductor layer (83), the GaN layer is Mg-doped, and the doping concentration of the GaN layer is 1 × 10⁻⁶. 19 cm -3 Up to 1×10 20 cm -3 Al E Ga 1-E The N layer is Mg-doped, and Al E Ga 1-E The doping concentration of the N-layer is 1×10⁻⁶. 19 cm -3 Up to 1×10 20 cm -3 .

8. The preparation method according to claim 7, characterized in that, The preparation method is carried out in a reaction chamber. The top of the reaction chamber is provided with a spray head (90). The sidewall of the spray head (90) includes a first annular injection area (91), a second annular injection area (92), a third annular injection area (93), a fourth annular injection area (94), and a fifth annular injection area (95) arranged sequentially from bottom to top in the vertical direction. The first annular injection area (91), the second annular injection area (92), the third annular injection area (93), the fourth annular injection area (94), and the fifth annular injection area (95) are all provided with multiple spaced airflow injection holes. Growing an n-type GaN layer (40) on a substrate (10) includes: Ammonia gas is injected into the reaction chamber from the first annular injection zone (91), the third annular injection zone (93), and the fifth annular injection zone (95), and an MO source is injected into the reaction chamber from the second annular injection zone (92) and the fourth annular injection zone (94). The flow rate ratio of the first annular injection zone (91), the second annular injection zone (92), the third annular injection zone (93), the fourth annular injection zone (94), and the fifth annular injection zone (95) is controlled to be 11.a:28.b:11.c:28.d:20.e, where a+b+c+d+e=20. Growing a shallow well layer (60) on the surface of the n-type GaN layer (40) includes: Ammonia gas is injected into the reaction chamber from the first annular injection zone (91), the third annular injection zone (93), and the fifth annular injection zone (95), and an MO source is injected into the reaction chamber from the second annular injection zone (92) and the fourth annular injection zone (94). The flow rate ratio of the first annular injection zone (91), the second annular injection zone (92), the third annular injection zone (93), the fourth annular injection zone (94), and the fifth annular injection zone (95) is controlled to be 21.a:18.b:19.c:19.d:21.e, where a+b+c+d+e=20. Growing a multi-quantum-well layer (70) on the surface of the shallow well layer (60) includes: Ammonia gas is injected into the reaction chamber from the first annular injection zone (91), the third annular injection zone (93), and the fifth annular injection zone (95), and an MO source is injected into the reaction chamber from the second annular injection zone (92) and the fourth annular injection zone (94). The flow rate ratio of the first annular injection zone (91), the second annular injection zone (92), the third annular injection zone (93), the fourth annular injection zone (94), and the fifth annular injection zone (95) is controlled to be 21.a:18.b:19.c:19.d:21.e, where a+b+c+d+e=20. Growing a p-type aluminum-containing semiconductor layer (83) on the surface of the multi-quantum-well layer (70) includes: Ammonia is injected into the reaction chamber from the first annular injection zone (91), the third annular injection zone (93), and the fifth annular injection zone (95), and an MO source is injected into the reaction chamber from the second annular injection zone (92) and the fourth annular injection zone (94). The flow rate ratio of the first annular injection zone (91), the second annular injection zone (92), the third annular injection zone (93), the fourth annular injection zone (94), and the fifth annular injection zone (95) is controlled to be 20.a:19.b:20.c:19.d:21.e, where a+b+c+d+e=10.

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