A sapphire gallium nitride-based red light epitaxial wafer structure and a preparation method thereof

Abstract

The present invention discloses a sapphire gallium nitride-based red light epitaxial wafer structure and a preparation method thereof, belonging to the field of semiconductor technology, including: a patterned sapphire substrate, a GaN substrate, an n-type AlGaN, an InGaN quantum well, an AlGaN electron blocking layer, a p-type GaN, an ITO, and a first electrode which are sequentially stacked; a second electrode is arranged on the n-type AlGaN; the InGaN quantum well, the AlGaN electron blocking layer, the p-type GaN, and the ITO form a red light enhancement structure; a plurality of circular through holes determined based on the light scattering theory and the quantum-confined Stark effect are vertically penetrated through the red light enhancement structure between the first electrode and the second electrode; when a voltage is applied between the first electrode and the second electrode, the generated electrons and holes recombine in the InGaN quantum well to generate red light, effectively improving the quality of the red light epitaxial wafer.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor technology, and particularly relates to a sapphire gallium nitride-based red light epitaxial wafer structure and a preparation method thereof. Background Art

[0002] The sapphire gallium nitride-based red light epitaxial wafer structure usually consists of three main parts: a substrate layer (sapphire substrate), an epitaxial layer (gallium nitride GaN epitaxial layer), and a red light emitting layer. The sapphire substrate provides a mechanical support and a heat conduction channel, while the gallium nitride epitaxial layer is grown epitaxially on the substrate to provide a high-quality crystal structure. The red light emitting layer is the core layer of the epitaxial wafer, where red light emission is achieved by doping or adjusting the material.

[0003] The sapphire gallium nitride-based red light epitaxial wafer structure can significantly improve the efficiency and performance of red light epitaxial wafers. As a substrate material, sapphire can not only provide good lattice matching, reduce defects, but also improve the device life through efficient heat dissipation performance. The gallium nitride material has excellent optoelectronic properties and strong luminous efficiency in the red light band, making this structure have a broad market prospect in applications such as display and lighting.

[0004] However, in the process of designing the size of the existing sapphire gallium nitride-based red light epitaxial wafer structure, the size of the epitaxial wafer structure is often determined through long-term experiments. It is impossible to simultaneously take into account multiple advantages such as high recombination efficiency, low stress, and high light extraction efficiency only through long-term experiments, resulting in low production efficiency and difficult quality assurance. Summary of the Invention

[0005] In order to solve the technical problem that in the process of designing the size of the existing sapphire gallium nitride-based red light epitaxial wafer structure, the size of the epitaxial wafer structure is often determined through long-term experiments, and it is impossible to simultaneously take into account multiple advantages such as high recombination efficiency, low stress, and high light extraction efficiency only through long-term experiments, resulting in low production efficiency and difficult quality assurance, the present invention provides a sapphire gallium nitride-based red light epitaxial wafer structure and a preparation method thereof.

[0006] In the first aspect, the present invention provides a sapphire gallium nitride-based red light epitaxial wafer structure, including: a patterned sapphire substrate, a GaN substrate, an n-type AlGaN, an InGaN quantum well, an AlGaN electron blocking layer, a p-type GaN, an ITO, a first electrode, and a second electrode;

[0007] The patterned sapphire substrate, the GaN substrate, the n-type AlGaN, the InGaN quantum well, the AlGaN electron blocking layer, the p-type GaN, the ITO, and the first electrode are sequentially stacked;

[0008] The second electrode is disposed on the n-type AlGaN;

[0009] The InGaN quantum well, the AlGaN electron blocking layer, the p-type GaN, and the ITO form a red light enhancement structure;

[0010] A plurality of circular through holes determined based on the light scattering theory and the quantum-confined Stark effect are provided through the red light enhancement structure in the vertical direction between the first electrode and the second electrode. Among them, the aperture diameters of each of the circular through holes are equal, and the spacing distances between adjacent circular through holes are equal;

[0011] When voltages are applied to the first electrode and the second electrode, the generated electrons and holes recombine in the InGaN quantum well to generate red light.

[0012] In a second aspect, the present invention provides a method for preparing a sapphire gallium nitride-based red light epitaxial wafer structure, and the method includes:

[0013] S1: Growing the GaN substrate on the patterned sapphire substrate by MOCVD deposition, and the growth temperature is 720 °C;

[0014] S2: Sequentially growing the n-type AlGaN, InGaN quantum well, AlGaN electron blocking layer, and p-type GaN at 920 °C. Among them, the thickness of the AlGaN electron blocking layer is 12 nm;

[0015] S3: Depositing the ITO at 350 °C;

[0016] S4: Exposing the n-type AlGaN by inductively coupled plasma etching;

[0017] S5: Depositing the first electrode and the second electrode on the ITO and the n-type AlGaN respectively to obtain the sapphire gallium nitride-based red light epitaxial wafer structure.

[0018] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0019] In an embodiment of the present invention, an AlGaN electron blocking layer is added on the basis of the structure of a conventional sapphire gallium nitride-based red light epitaxial wafer, which effectively avoids the diffusion of electrons in the quantum well region, effectively prevents the diffusion of electrons in the quantum well region, reduces the electron leakage phenomenon, and improves the recombination efficiency of electrons and holes. Moreover, on the red light enhancement structure composed of an InGaN quantum well, the AlGaN electron blocking layer, the p-type GaN, and the ITO, and on the non-covered area of the non-first electrode and the non-second electrode, a plurality of circular through holes determined based on the light scattering theory and the quantum-confined Stark effect are vertically penetrated. The aperture diameters of each circular through hole are equal, and the interval distances between adjacent circular through holes are equal. By arranging circular through holes designed based on the light scattering theory and the quantum-confined Stark effect on the red light enhancement structure, the propagation path of light can be optimized, and the light extraction efficiency can be improved. The equal aperture diameters and interval distances contribute to uniform light scattering, reduce light reflection and loss, improve the overall light emission effect of the epitaxial wafer, and at the same time reduce stress concentration, enhance the stability and reliability of the epitaxial wafer. Furthermore, the light output power of the red light epitaxial wafer is enhanced, the light emission efficiency of the device is improved, and energy loss is reduced, thereby improving the performance and stability of the overall device. While ensuring the production quality of the epitaxial wafer, the parameters of the epitaxial wafer are determined based on theoretical design, and the production quality and design efficiency of the epitaxial wafer are improved. Description of the Drawings

[0020] The above characteristics, technical features, advantages and implementation manners of the present invention will be further described below in a clear and understandable manner in combination with the drawings to illustrate the preferred embodiments.

[0021] Figure 1 It is a schematic structural diagram of a sapphire gallium nitride-based red light epitaxial wafer structure provided by the present invention;

[0022] Figure 2 It is a schematic structural diagram of another sapphire gallium nitride-based red light epitaxial wafer structure provided by the present invention;

[0023] Figure 3 It is a schematic flowchart of a preparation method of a sapphire gallium nitride-based red light epitaxial wafer structure provided by the present invention. Detailed Embodiments

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific embodiments of the present invention will be described below with reference to the drawings. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts, and other embodiments can also be obtained.

[0025] Embodiment 1

[0026] In one embodiment, referring to the accompanying drawings of the specification Figure 1 , a schematic structural diagram of a sapphire gallium nitride-based red light epitaxial wafer structure provided by the present invention is shown. Referring to the accompanying drawings of the specification Figure 2 is a schematic structural diagram of another sapphire gallium nitride-based red light epitaxial wafer structure provided by the present invention.

[0027] Figure 1 Structurally, the first electrode and the second electrode are composed of multiple layers of materials such as ITO, electrodes, p-type GaN, AlGaN electron blocking layer, InGaN quantum well, n-type AlGaN, and GaN substrate. The dotted part is the penetration path of the circular through-hole. The InGaN quantum well serves as the core layer and is responsible for emitting light. The AlGaN electron blocking layer is used to prevent the diffusion of electrons and improve the recombination efficiency of electrons and holes. The bottom is the sapphire substrate, which provides mechanical support. Figure 2 is Figure 1 the top view of Figure 2 i.e., the top view of the sapphire gallium nitride-based red light epitaxial wafer structure, Figure 2 showing multiple circular through-holes perpendicular to the electrode region. These holes are designed based on the light scattering theory and the quantum-confined Stark effect. By setting these through-holes, the light extraction path can be optimized, light reflection can be reduced, and the light output efficiency of the epitaxial wafer can be improved. At the same time, the uniform aperture and spacing design can reduce the stress concentration of the epitaxial wafer and enhance its stability and production quality.

[0028] A sapphire gallium nitride-based red light epitaxial wafer structure provided by the present invention includes: a patterned sapphire substrate, a GaN substrate, an n-type AlGaN, an InGaN quantum well, an AlGaN electron blocking layer, a p-type GaN, ITO, a first electrode, and a second electrode.

[0029] Among them, the sapphire gallium nitride-based red light epitaxial wafer structure includes multiple important layers. First, the patterned sapphire substrate provides mechanical support and helps with light propagation. The GaN substrate serves as a support structure to enhance heat conductivity. The n-type AlGaN and p-type GaN respectively form the electron and hole injection layers to ensure current injection into the quantum well. The InGaN quantum well is the core region for emitting light and generates red light. The AlGaN electron blocking layer effectively inhibits electron diffusion and improves the recombination efficiency. The ITO layer serves as a transparent electrode to enhance the uniform distribution of current. Finally, the first and second electrodes are used to provide current injection. Such a structural design can significantly improve the light efficiency, brightness, and stability of the red light epitaxial wafer, and reduce energy loss. The reasonable combination and optimization of each layer provide a reliable guarantee for the high-efficiency light emission and long lifespan of the epitaxial wafer device, making it have broad application prospects in the fields of display, lighting, etc.

[0030] A patterned sapphire substrate, a GaN substrate, an n-type AlGaN, an InGaN quantum well, an AlGaN electron blocking layer, a p-type GaN, ITO, and a first electrode are sequentially stacked.

[0031] A second electrode is disposed on the n-type AlGaN.

[0032] The InGaN quantum well, the AlGaN electron blocking layer, the p-type GaN, and ITO form a red light enhancement structure.

[0033] In the vertical direction of the red light enhancement structure between the first electrode and the second electrode, a plurality of circular through-holes determined based on the light scattering theory and the quantum-confined Stark effect are penetrated. Among them, the aperture diameters of each circular through-hole are equal, and the spacing distances between adjacent circular through-holes are equal.

[0034] Among them, the light scattering theory mainly describes the propagation of light in a medium and its interaction with matter, especially the scattering phenomenon that occurs when light is in an irregular structure on the surface, interface, or material. By reasonably designing the optical structure, light can be reflected or refracted through different paths, thereby improving the light extraction efficiency and reducing light loss. The quantum-confined Stark effect refers to the fact that in a semiconductor material at the nanoscale, due to the influence of quantum effects, the energy levels of electrons and holes shift, resulting in the confinement of the electronic state and optical properties of the material. The Stark effect can control the distribution of electrons and holes by applying an external electric field, improve the carrier recombination efficiency, and thus enhance the light emission effect.

[0035] In this structure, based on the design of the light scattering theory and the quantum-confined Stark effect, by setting a plurality of circular through-holes in the red light enhancement structure, the light propagation path is optimized. The apertures and spacings of these through-holes are equal, effectively improving the light extraction efficiency and reducing the reflection loss. The quantum confinement effect further improves the carrier recombination efficiency, thereby enhancing the emission brightness and stability of red light. At the same time, the uniform through-hole design helps to relieve the stress of the material and enhance the long-term stability and reliability of the structure.

[0036] When a voltage is applied to the first electrode and the second electrode, the generated electrons and holes recombine in the InGaN quantum well to generate red light.

[0037] Specifically, the patterned sapphire substrate and the GaN substrate provide mechanical support and good thermal conductivity, ensuring the stable operation of the device. The n-type AlGaN and p-type GaN layers respectively provide electron and hole injection channels, ensuring the injection of carriers into the InGaN quantum well. The InGaN quantum well is the core region for red light emission, while the AlGaN electron blocking layer effectively prevents the diffusion of electrons, improving the carrier recombination efficiency. The ITO transparent electrode further distributes the current evenly, enhancing the light emission efficiency. To further improve the light extraction efficiency, multiple circular through-holes are designed in the red light enhancement structure. Based on the light scattering theory and the quantum-confined Stark effect, the light propagation path is optimized, reducing the reflection loss of light and improving the carrier recombination efficiency, thereby enhancing the brightness and stability of the red light. Finally, this structure can significantly improve the light efficiency, brightness, and stability of the red light epitaxial wafer, reduce energy loss, extend the lifespan of the epitaxial wafer device, and has broad application prospects, especially in the fields of display and lighting.

[0038] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0039] In the embodiment of the present invention, an AlGaN electron blocking layer is added on the basis of the structure of the traditional sapphire gallium nitride-based red light epitaxial wafer, effectively avoiding the diffusion of electrons in the quantum well region, preventing the diffusion of electrons in the quantum well region, reducing the electron leakage phenomenon, and improving the recombination efficiency of electrons and holes. Moreover, on the red light enhancement structure composed of InGaN quantum well, AlGaN electron blocking layer, p-type GaN, and ITO, and not in the region covered by the non-first electrode and the non-second electrode, a plurality of circular through-holes determined based on the light scattering theory and the quantum-confined Stark effect are vertically penetrated. The aperture diameters of each circular through-hole are equal, and the spacing distances between adjacent circular through-holes are equal. By setting circular through-holes designed based on the light scattering theory and the quantum-confined Stark effect on the red light enhancement structure, the light propagation path can be optimized, and the light extraction efficiency can be improved. The equal aperture diameters and spacing distances help to scatter the light evenly, reduce the reflection and loss of light, improve the overall light emission effect of the epitaxial wafer, and at the same time reduce the stress concentration, enhancing the stability and reliability of the epitaxial wafer. Furthermore, the light output power of the red light epitaxial wafer is enhanced, the light emission efficiency of the device is improved, and the energy loss is reduced, thereby improving the performance and stability of the overall device. While ensuring the production quality of the epitaxial wafer, the parameters of the epitaxial wafer are determined based on theoretical design, improving the production quality and design efficiency of the epitaxial wafer.

[0040] In a possible implementation manner, the component ratio between the Al component content and the Ga component content in the AlGaN electron blocking layer is 1:9.

[0041] It should be noted that the ratio of the Al component content to the Ga component content in the AlGaN electron blocking layer is 1:9, which means that the main component of this layer is Ga. Such a ratio can ensure a lower energy band structure and higher conductivity while maintaining good electron blocking performance, optimize the recombination efficiency of electrons and holes, and enhance the emission effect of red light.

[0042] Both the first electrode and the second electrode are metal contact layers composed of an Al bottom layer, a Ni bonding layer, and an Au top layer, or composed of a Cr bottom layer, a Pt bonding layer, and an Au top layer.

[0043] It can be understood that the first electrode and the second electrode adopt metal contact layers composed of an Al bottom layer, a Ni bonding layer, and an Au top layer, or composed of a Cr bottom layer, a Pt bonding layer, and an Au top layer. Such a design can ensure good contact between the electrode and the epitaxial wafer through the combination of multiple metal materials. The bottom metal (such as Al or Cr) provides excellent adhesion and conductivity, the bonding layer (such as Ni or Pt) helps to enhance the bonding force between the metal and the semiconductor layer, and the Au top layer provides good conductivity and stability, preventing electrode oxidation or corrosion and ensuring long-term stable current transmission.

[0044] In a possible implementation, the doping sources of n-type AlGaN and p-type GaN are disilane and Cp2Mg respectively.

[0045] In the actual application process, the doping sources of n-type AlGaN and p-type GaN are disilane (Si2H6) and Cp2Mg (magnesium alkane compound) respectively. Disilane, as an n-type doping source, can effectively provide electrons and improve the conductivity of the n-type GaN layer. Cp2Mg, on the other hand, serves as a p-type doping source, which can provide magnesium ions and enhance the hole concentration in the p-type GaN layer, thereby improving the current injection characteristics. Through this doping method, the conductivity of the n-type and p-type GaN layers is optimized, which helps to improve the working efficiency and stability of the device.

[0046] In a possible implementation, the determination methods of the thickness and In component content of the InGaN quantum well are specifically as follows:

[0047] ;

[0048] where x represents the In component content, and respectively represent and the band gaps of represent the red light wavelength the required band gap of represents the thickness of the InGaN quantum well, represents the minimum thickness of the InGaN quantum well, and respectively represent the stress and carrier recombination efficiency of the InGaN quantum well, and respectively represent the maximum stress threshold and the minimum carrier recombination efficiency threshold of the InGaN quantum well, 、 and respectively represent the lattice constants of InGaN, GaN, and InN, and respectively represent the radiative recombination lifetime and the non-radiative recombination lifetime related to the thickness of the InGaN quantum well.

[0049] In the actual application process, this method of determining the thickness and In composition content of the InGaN quantum well can accurately optimize the design of the quantum well by comprehensively considering factors such as bandgap, stress, carrier recombination efficiency, and the lattice constant of the material. Specifically, the relationship between the bandgap and the required bandgap of the red light wavelength can ensure that the emission wavelength of the light meets the requirements. The balance between stress and carrier recombination efficiency guarantees that the quantum well can effectively improve the light emission efficiency during operation and reduce unnecessary energy loss. At the same time, by controlling the minimum thickness and the maximum stress threshold of the quantum well, the performance degradation caused by excessive stress in the material can be effectively avoided, and the stability and lifetime of the device can be improved. The quantum well designed in this way not only improves the light emission efficiency of the red light epitaxial wafer but also ensures long-term stable operation, with higher reliability and performance.

[0050] It should be noted that those skilled in the art can set the magnitudes of the maximum stress threshold and the minimum carrier recombination efficiency threshold according to actual needs, and the present invention does not make any limitations in this regard.

[0051] It is understandable that the bandgap of the InGaN quantum well decreases as the In composition content increases. Increasing the In content can reduce the energy band width of the quantum well, thereby making the emission wavelength longer. Therefore, for red light emission, a higher In composition content (such as an In content between 0.2 - 0.3) helps to achieve the desired red light wavelength (for example, around 634 nm). When the In content is high, due to the difference in lattice constants between In and Ga (the lattice constant of InN is larger than that of GaN), it will lead to an increase in stress. If the thickness of the quantum well is too large, it may cause stress accumulation, resulting in cracks or bandgap bending phenomena, thus affecting the light emission efficiency. When the In content is high, in order to control stress, it is usually necessary to reduce the thickness of the quantum well. This can reduce the problems of stress and bandgap bending caused by excessive thickness. The thickness of the quantum well directly affects the recombination efficiency of carriers. When the quantum well is too thin, the carriers may not have enough time to recombine, thus affecting the light emission intensity. When the quantum well is too thick, the recombination efficiency will be reduced due to excessive stress and bandgap bending. Therefore, the thickness of the quantum well must be precisely controlled, especially in the case of high In composition content. For InGaN quantum wells with a high In content, it is usually necessary to reduce the thickness of the quantum well while adjusting the composition and thickness of the quantum well to ensure both effective stress control and sufficient carrier recombination and high - efficiency light emission. Good light emission performance can be achieved at high In content through stress - relief techniques (such as introducing an AlGaN buffer layer or adjusting the thickness of the GaN template) and quantum well thickness control (such as using a thinner quantum well).

[0052] In a possible implementation, the interval distance and aperture diameter are determined with the goal that the light extraction efficiency of the sapphire - based gallium nitride red light epitaxial wafer structure meets a preset light extraction efficiency.

[0053] The interval distance and aperture diameter are specifically as follows:

[0054] ;

[0055] where p represents the interval distance, d represents the aperture diameter, n represents the refractive index of InGaN, represents the emission light wavelength, i.e., the red light wavelength, represents the light extraction efficiency, represents the preset light extraction efficiency, and e represents the natural constant.

[0056] In the actual application process, through this method, the aperture diameter and the spacing distance of the quantum well can be precisely designed according to the required light extraction efficiency. Specifically, by adjusting the aperture diameter and the hole pitch, the best light scattering effect can be achieved, thereby improving the light extraction efficiency. The determination of the spacing distance and the aperture diameter is based on the refractive index of the InGaN material and the emission wavelength of red light. Through this optimized design, the light loss can be minimized, the output brightness of red light can be enhanced, and the overall light efficiency can be improved. In addition, the precise control of the light extraction efficiency ensures that the epitaxial wafer has higher performance and stability in actual applications, thereby increasing the service life and reliability of the device.

[0057] It should be noted that those skilled in the art can set the size of the preset light extraction efficiency according to actual needs, and the present invention does not make any limitations here.

[0058] Specifically, by optimizing the design of each layer of the sapphire gallium nitride-based red light epitaxial wafer structure, the light emission efficiency, brightness and stability of the red light epitaxial wafer are improved. The structure includes a patterned sapphire substrate, a GaN substrate, an n-type AlGaN, an InGaN quantum well, an AlGaN electron blocking layer, a p-type GaN, an ITO, and a first and a second electrode and other multi-layer materials. The quantum well, as the core light-emitting layer, cooperates with the AlGaN electron blocking layer to effectively control the electron diffusion and enhance the recombination efficiency. In order to further optimize the light extraction efficiency, it is designed to set a plurality of circular through holes in the red light enhancement structure, and the light propagation path is improved through the light scattering theory and the quantum-confined Stark effect, reducing the reflection loss and enhancing the light output. In addition, precisely controlling the thickness and In composition content of the quantum well can effectively solve the stress problem, ensure efficient carrier recombination, and improve the red light emission effect. Finally, through such a structural design, not only the light efficiency and stability are improved, but also the long-term reliability and application prospects of the device are enhanced.

[0059] Example 2

[0060] In one embodiment, referring to the attached Figure 3 illustrates a schematic flow chart of a method for preparing a sapphire gallium nitride-based red light epitaxial wafer structure provided by the present invention.

[0061] A method for preparing a sapphire gallium nitride-based red light epitaxial wafer structure provided by the present invention, the method includes:

[0062] S1: Growing a GaN substrate on a patterned sapphire substrate by MOCVD deposition, and the growth temperature is 720 °C.

[0063] Specifically, a GaN substrate is grown on a patterned sapphire substrate using metalorganic chemical vapor deposition (MOCVD) technology. The growth temperature is set at 720 °C, which helps to improve the crystal quality and uniformity of the GaN thin film. Through MOCVD deposition, the thickness and doping level of the GaN substrate can be precisely controlled to ensure good mechanical properties and thermal conductivity, providing a solid foundation for the subsequent growth of other layers.

[0064] In a possible implementation, the thickness of the GaN substrate is 2.6 μm.

[0065] Optionally, the reactor pressure during deposition can be set to 100 kPa.

[0066] It should be noted that the thickness of the GaN substrate is 2.6 μm, which can provide sufficient mechanical strength and thermal conductivity to ensure the stability of the subsequent grown layers. During the deposition process, the reactor pressure is set to 100 kPa, which helps to optimize the gas reaction rate and ensure the quality and crystal structure of the GaN substrate. Appropriate pressure control can improve the uniformity of the deposition process, reduce defects, and ultimately ensure the performance of the epitaxial wafer.

[0067] In a possible implementation, after S1 and before S2, it further includes:

[0068] S1A: Grow an InGaN decomposition layer with a thickness of 2 nm at 835 °C, where the In component content of the InGaN decomposition layer is less than 30%.

[0069] It should be noted that by growing an InGaN decomposition layer with a thickness of 2 nm at 835 °C, the purpose is to provide a transition layer between the GaN substrate and the subsequent InGaN quantum wells. The In component content of this decomposition layer is less than 30%, which can reduce the lattice mismatch between InGaN and the GaN substrate, relieve stress, improve the crystal quality, provide a better foundation for the subsequent quantum well structure, and ensure the performance and stability of the red LED.

[0070] S2: Sequentially grow an n-type AlGaN, an InGaN quantum well, an AlGaN electron blocking layer, and a p-type GaN at 920 °C, where the thickness of the AlGaN electron blocking layer is 12 nm.

[0071] Specifically, an n-type AlGaN, an InGaN quantum well, an AlGaN electron blocking layer, and a p-type GaN are sequentially grown at 920 °C to construct a structure with high-efficiency light emission and current injection characteristics. The n-type AlGaN layer provides an electron injection channel, and the InGaN quantum well serves as a light-emitting layer to generate red light. The AlGaN electron blocking layer has a thickness of 12 nm, which is used to prevent electron leakage, optimize the recombination efficiency of electrons and holes, and thus enhance the light emission intensity. The p-type GaN layer is used to provide a hole injection channel, ensuring effective current injection and improving the overall device performance.

[0072] Optionally, the thickness of the InGaN quantum well is , and the thicknesses of the n-type AlGaN and p-type GaN can be set to 80 nm and 62 nm respectively. The thickness of the AlGaN electron blocking layer can be set to 12 nm.

[0073] S3: Deposit ITO at 350 °C.

[0074] In one possible implementation, the thickness of the ITO is 100 nm.

[0075] It should be noted that the ITO (indium tin oxide) layer is deposited at 350 °C to form a transparent electrode. As a transparent conductive material, the ITO layer has good electrical conductivity and light transmittance, can evenly distribute current, reduce the concentrated loss of current, and ensure the effective emission of red light. The thickness of the ITO layer is 100 nm, and an appropriate thickness can balance the electrical conductivity and light transmittance, ensuring the high-efficiency performance of the device.

[0076] S4: Expose the n-type AlGaN by inductively coupled plasma etching.

[0077] Specifically, the n-type AlGaN layer is exposed by inductively coupled plasma etching (ICP etching) technology. This etching process uses high-energy plasma to precisely remove unwanted materials, exposing the surface of the n-type AlGaN, ensuring good contact with the subsequent electrodes. ICP etching can achieve high-precision and high-selectivity etching, avoid damaging the underlying materials, help improve the quality of the epitaxial wafer, and ensure the stability and effectiveness of the current injection channel.

[0078] S5: Deposit a first electrode and a second electrode on the ITO and the n-type AlGaN respectively to obtain a sapphire gallium nitride-based red light epitaxial wafer structure.

[0079] Specifically, the first electrode and the second electrode are respectively deposited on the ITO layer and the n-type AlGaN layer to achieve effective current injection. By depositing metal electrodes on these layers, good electrical conductivity and stable current transmission can be ensured. The first electrode is usually in contact with the transparent ITO layer, while the second electrode is in contact with the n-type AlGaN layer, ensuring that current flows smoothly through the entire LED structure. This process completes the final construction of the sapphire gallium nitride-based red light epitaxial wafer structure, ensuring the efficient operation and stable performance of the device.

[0080] It should be noted that for circular through-holes, a standard lithography process (such as step-and-repeat exposure, nanoimprint lithography, electron beam lithography, deep ultraviolet lithography, laser direct writing lithography, two-photon absorption lithography, etc.) can be used to fabricate a micropore array on the device substrate.

[0081] In the actual application process, first, a GaN substrate is grown on the patterned sapphire substrate using MOCVD deposition technology to ensure the quality and thermal conductivity of the substrate. Then, an InGaN decomposition layer is grown at a higher temperature to control the material quality and adjust the thickness and In composition content of the InGaN quantum well to ensure the wavelength of red light emission. Subsequently, by precisely controlling the growth conditions, n-type AlGaN, InGaN quantum well, AlGaN electron blocking layer, and p-type GaN are sequentially deposited to form a structure with excellent electronic and optical properties. Next, an ITO layer is deposited to provide a transparent electrode, and the n-type AlGaN layer is exposed through etching to ensure effective current injection. Finally, the first electrode and the second electrode are deposited on the ITO and the n-type AlGaN respectively to complete the preparation of the sapphire gallium nitride-based red light epitaxial wafer structure. This process realizes efficient light extraction and stable current injection by precisely controlling the thickness and doping of each layer, improving the light efficiency, stability, and service life of the LED.

[0082] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0083] The above embodiments only represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A sapphire gallium nitride-based red light epitaxial wafer structure, characterized in that, Including: Patterned sapphire substrate, GaN substrate, n-type AlGaN, InGaN quantum well, AlGaN electron blocking layer, p-type GaN, ITO, first electrode and second electrode; The patterned sapphire substrate, the GaN substrate, the n-type AlGaN, the InGaN quantum well, the AlGaN electron blocking layer, the p-type GaN, the ITO and the first electrode are sequentially stacked; The second electrode is disposed on the n-type AlGaN; The InGaN quantum well, the AlGaN electron blocking layer, the p-type GaN and the ITO form a red light enhancement structure; A plurality of circular through holes determined based on the light scattering theory and the quantum-confined Stark effect are vertically penetrated in the vertical direction of the red light enhancement structure between the first electrode and the second electrode, wherein the aperture diameters of each of the circular through holes are equal, and the spacing distances between adjacent circular through holes are equal; When a voltage is applied between the first electrode and the second electrode, the generated electrons and holes recombine in the InGaN quantum well to generate red light; The determination method of the thickness and In component content of the InGaN quantum well is specifically: ； Among them, x represents the In component content, and respectively represent and the band gaps of represents the red light wavelength the required band gap, represents the thickness of the InGaN quantum well, represents the minimum thickness of the InGaN quantum well, and respectively represent the stress and carrier recombination efficiency of the InGaN quantum well, and respectively represent the maximum stress threshold and the minimum carrier recombination efficiency threshold of the InGaN quantum well, 、 and respectively represent the lattice constants of InGaN, GaN and InN, and respectively represent the radiative recombination lifetime and the non-radiative recombination lifetime related to the InGaN quantum well thickness.

2. The structure of the sapphire gallium nitride-based red light epitaxial wafer according to claim 1, wherein, The component ratio between the Al component content and the Ga component content in the AlGaN electron blocking layer is 1:

9.

3. The structure of the sapphire-based gallium nitride red light epitaxial wafer according to claim 2, wherein, Both the first electrode and the second electrode are metal contact layers composed of an Al bottom layer, a Ni bonding layer and an Au top layer or composed of a Cr bottom layer, a Pt bonding layer and an Au top layer.

4. The sapphire gallium nitride-based red light epitaxial wafer structure according to claim 3, characterized in that, The doping sources of the n-type AlGaN and the p-type GaN are disilane and Cp2Mg respectively.

5. The sapphire gallium nitride-based red light-emitting epitaxial wafer structure according to claim 4, characterized in that, The spacing distance and the aperture diameter are determined with the goal that the light extraction efficiency of the sapphire gallium nitride based red light epitaxial wafer structure meets a preset light extraction efficiency; The spacing distance and the aperture diameter are specifically: ； Among them, p represents the spacing distance, d represents the aperture diameter, and n represents the refractive index of InGaN. represents the emission light wavelength, i.e., the red light wavelength. represents the light extraction efficiency. represents the preset light extraction efficiency, and e represents the natural constant.

6. A method for preparing a sapphire gallium nitride-based red light epitaxial wafer structure as described in claim 5, characterized in that, The method includes: S1: Growing the GaN substrate on the patterned sapphire substrate by MOCVD deposition, and the growth temperature is 720 °C; S2: Sequentially growing the n-type AlGaN, InGaN quantum well, AlGaN electron blocking layer, p-type GaN at 920 °C, wherein the thickness of the AlGaN electron blocking layer is 12 nm; S3: Depositing the ITO at 350 °C; S4: Exposing the n-type AlGaN by inductively coupled plasma etching; S5: Depositing the first electrode and the second electrode on the ITO and the n-type AlGaN respectively to obtain the sapphire gallium nitride based red light epitaxial wafer structure.

7. The preparation method according to claim 6, characterized in that, The thickness of the GaN substrate is 2.6 μm.

8. The preparation method according to claim 6, characterized in that, After the S1 and before the S2, it further includes: S1A: Growing an InGaN decomposition layer with a thickness of 2 nm at 835 °C, wherein the In component content of the InGaN decomposition layer is less than 30%.

9. The preparation method according to claim 6, characterized in that, The thickness of the ITO is 100 nm.

Images