Epitaxial structure of a group III nitride semiconductor light-emitting element

Abstract

This invention relates to the field of semiconductor optoelectronic device technology, specifically disclosing an epitaxial structure for a group III nitride semiconductor light-emitting element. The epitaxial structure of this group III nitride semiconductor light-emitting element, from bottom to top, includes a substrate, an n-type semiconductor, a quantum well, a p-type semiconductor, and a high electron mobility contact layer above the p-type semiconductor. The peak position of the high electron mobility contact layer has a decreasing angle φ towards the quantum well, the valley position of the peak velocity electric field of the high electron mobility contact layer has an increasing angle β towards the quantum well, the valley position of the hole mobility of the high electron mobility contact layer has an increasing angle γ towards the quantum well, and the valley position of the longitudinal sound velocity of the high electron mobility contact layer has an increasing angle θ towards the quantum well. This epitaxial structure of the group III nitride semiconductor light-emitting element can improve hole migration efficiency and injection efficiency, and reduce voltage variation under aging conditions.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor optoelectronic device technology, specifically relating to an epitaxial structure of a group III nitride semiconductor light-emitting element. Background Technology

[0002] Semiconductor components, especially semiconductor light-emitting components, have a wide range of adjustable wavelengths, high luminous efficiency, energy saving and environmental protection, a long lifespan of over 100,000 hours, small size, multiple application scenarios, and strong design flexibility. As a result, they have gradually replaced incandescent and fluorescent lamps and become the light source for ordinary household lighting. They are also widely used in new scenarios, such as indoor high-resolution displays, outdoor displays, Mini-LED, Micro-LED, mobile phone TV backlights, backlighting, street lights, car headlights, daytime running lights, car interior ambient lighting, flashlights, and other application areas.

[0003] Traditional nitride semiconductors are grown on sapphire substrates, resulting in large lattice and thermal mismatches, leading to high defect density and polarization effects, which reduce the luminous efficiency of semiconductor light-emitting devices. Simultaneously, the hole ionization efficiency of traditional nitride semiconductors is far lower than that of electron ionization, resulting in a hole concentration that is more than an order of magnitude lower than the electron concentration. Excess electrons overflow from the multiple quantum wells into the second conductivity type semiconductor, causing nonradiative recombination. The low hole ionization efficiency also makes it difficult for holes in the second conductivity type semiconductor to be effectively injected into the multiple quantum wells, leading to low hole injection efficiency and excessive electrons. The luminous efficiency of the quantum well is low; the nitride semiconductor structure has non-centrosymmetry, and strong spontaneous polarization will be generated along the c-axis direction. The piezoelectric polarization effect of lattice mismatch is superimposed to form an intrinsic polarization field; the intrinsic polarization field along the (001) direction causes a strong quantum confinement Stark effect in the multi-quantum well layer, causing band tilt and spatial separation of electron-hole wave functions, reducing the radiative recombination efficiency of electrons and holes; the refractive index, dielectric constant and other parameters of the semiconductor light-emitting element are greater than those of air, resulting in a smaller total reflection angle when the light emitted from the quantum well is emitted, and a lower light extraction efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide an epitaxial structure for a group III nitride semiconductor light-emitting element that is simple in structure and reasonably designed in order to solve the above-mentioned problems.

[0005] The present invention achieves the above objectives through the following technical solutions:

[0006] An epitaxial structure for a group III nitride semiconductor light-emitting element comprises, from bottom to top, a substrate, an n-type semiconductor, a quantum well, and a p-type semiconductor. A high electron mobility contact layer is located above the p-type semiconductor. The peak position of the high electron mobility contact layer descends towards the quantum well at an angle φ, the valley position of the peak velocity electric field of the high electron mobility contact layer ascends towards the quantum well at an angle β, the valley position of the hole mobility of the high electron mobility contact layer ascends towards the quantum well at an angle γ, and the valley position of the longitudinal sound velocity of the high electron mobility contact layer ascends towards the quantum well at an angle θ, where: 3°≤θ≤φ≤β≤γ≤87°.

[0007] Furthermore, the high electron mobility contact layer is any one or any combination of GaN, AlInGaN, AlGaN, InGaN, AlN, InN, and AlInN; the quantum well is a periodic structure composed of a well layer and a barrier layer, with a period number of 1 to 50.

[0008] The peak electron drift velocity distribution, peak velocity electric field distribution, covalent bond energy distribution, and longitudinal sound velocity distribution of the high electron mobility contact layer all exhibit a V-shaped distribution. The peak electron drift velocity of the p-type semiconductor is less than or equal to the peak electron drift velocity of the high electron mobility contact layer and less than or equal to the peak electron drift velocity of the quantum well's well layer.

[0009] Wherein, the covalent bond energy of the quantum well's well layer is less than or equal to the covalent bond energy of the high electron mobility contact layer and less than or equal to the covalent bond energy of the p-type semiconductor;

[0010] Wherein, the longitudinal sound velocity of the quantum well's well layer is less than or equal to the longitudinal sound velocity of the high electron mobility contact layer and less than or equal to the longitudinal sound velocity of the p-type semiconductor.

[0011] Furthermore, the p-type doping element of the high electron mobility contact layer is any one or any combination of elements such as Mg, Zn, Li, Na, and K; the thickness of the high electron mobility contact layer is 5 to 500 angstroms.

[0012] Further, the quantum well includes a first quantum well and a second quantum well; the quantum well is any one or any combination of GaN, InGaN, InN, AlInN, AlN, AlInGaN, AlGaN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, InGaP, SiC, Ga2O3, BN, and diamond; the thickness of the quantum well layer is 5–200 angstroms, and the thickness of the barrier layer is 10–500 angstroms.

[0013] Furthermore, the n-type semiconductor is any one or any combination of GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, Ga2O3, BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, and InGaP; the thickness of the n-type semiconductor is 50 to 90,000 angstroms.

[0014] Furthermore, the p-type semiconductor is any one or any combination of GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, Ga2O3, BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, and InGaP; the thickness of the p-type semiconductor is 10 to 80,000 angstroms.

[0015] Furthermore, the substrate includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, Mo, diamond, Cu, TiW, InP, and sapphire / SiO2 / SiN. x Composite substrate, sapphire / SiN x / SiO2 composite substrate, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiN x Any one of the following composite substrates: magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2, and LiGaO2.

[0016] The beneficial effects of this invention are as follows: By setting a high electron mobility contact layer above a p-type semiconductor and controlling the magnitude of the downward angle of the peak position of the peak electron drift velocity of the high electron mobility contact layer towards the quantum well, the upward angle of the valley position of the peak velocity electric field of the high electron mobility contact layer towards the quantum well, the upward angle of the valley position of the hole mobility of the high electron mobility contact layer towards the quantum well, and the upward angle of the valley position of the longitudinal sound velocity of the high electron mobility contact layer towards the quantum well, this invention reduces the work function of the high electron mobility contact layer and the ITO or metal electrode material, reduces the band order of the high electron mobility contact layer and the ITO or metal electrode material, improves hole migration efficiency and injection efficiency, reduces the voltage variation amplitude under aging conditions, and reduces the voltage variation amplitude after 1000 hours of aging. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the epitaxial structure of a group III nitride semiconductor light-emitting element according to an embodiment of the present invention.

[0018] In the figure: 100, substrate; 101, n-type semiconductor; 102, quantum well; 103, p-type semiconductor; 104, high electron mobility contact layer. Detailed Implementation

[0019] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0020] like Figure 1 As shown, an epitaxial structure of a group III nitride semiconductor light-emitting element includes, from bottom to top, a substrate 100, an n-type semiconductor 101, a quantum well 102, a p-type semiconductor 103, and a high electron mobility contact layer 104 above the p-type semiconductor 103. The peak position of the peak electron drift velocity of the high electron mobility contact layer 104 descends at an angle of φ towards the quantum well 102, the valley position of the peak velocity electric field of the high electron mobility contact layer 104 ascends at an angle of β towards the quantum well 102, the valley position of the hole mobility of the high electron mobility contact layer 104 ascends at an angle of γ towards the quantum well 102, and the valley position of the longitudinal sound velocity of the high electron mobility contact layer 104 ascends at an angle of θ towards the quantum well 102, wherein: 3°≤θ≤φ≤β≤γ≤87°.

[0021] It should be noted that a high electron mobility contact layer generally refers to a layer used in semiconductor devices to optimize electron mobility. This layer is designed to reduce the resistance of electrons in the contact area while increasing the electron mobility in that area, thereby improving device performance.

[0022] By controlling the angular relationship between peak electron drift rate, peak velocity electric field, hole mobility and longitudinal sound velocity, the device achieves an optimal balance between electrical and optical performance.

[0023] Furthermore, the high electron mobility contact layer 104 is any one or any combination of GaN, AlInGaN, AlGaN, InGaN, AlN, InN, and AlInN; the quantum well 102 is a periodic structure composed of a well layer and a barrier layer, with a period number of 1 to 50.

[0024] Among them, the peak electron drift velocity distribution, peak velocity electric field distribution, covalent bond energy distribution and longitudinal sound velocity distribution of the high electron mobility contact layer 104 all have V-shaped distributions, and the peak electron drift velocity of the p-type semiconductor 103 is less than or equal to the peak electron drift velocity of the high electron mobility contact layer 104 and the peak electron drift velocity of the well layer of the quantum well 102.

[0025] Among them, the relevant parameters of the high electron mobility contact layer 104 designed with a V-shaped distribution can optimize device performance in many aspects, improve stability, reduce energy consumption, enhance performance consistency, achieve application adaptation and promote technological innovation;

[0026] The well layer of quantum well 102 is typically designed to have a high electron drift velocity, while the electron drift velocity of the high electron mobility contact layer 104 is between that of the p-type semiconductor 103 and the quantum well 102. This hierarchical relationship helps to achieve superior electron transport performance in different regions;

[0027] By controlling the electron drift rate in different regions, the performance within the device can be matched and optimized. Ensuring that the electron drift rate of the high electron mobility contact layer 104 is within a suitable range helps to achieve performance balance and matching throughout the device.

[0028] The progressive relationship of electron drift rates in different regions helps improve the stability and reliability of devices. By controlling this relationship, the non-uniform distribution of electrons in the device can be reduced, thereby improving the device's stability and reliability.

[0029] Among them, the covalent bond energy of the well layer of quantum well 102 is less than or equal to the covalent bond energy of the high electron mobility contact layer 104 and less than or equal to the covalent bond energy of the p-type semiconductor 103;

[0030] It should be noted that the well layer of quantum well 102 is typically designed to have a low covalent bond energy, while the covalent bond energy of the high electron mobility contact layer 104 is between that of the p-type semiconductor 103 and the quantum well 102. This progressive relationship facilitates the matching and optimization of energy levels in different regions;

[0031] By controlling the covalent bond energy in different regions, the band structure and electron transport performance within the device can be tuned. Ensuring that the covalent bond energy of the high electron mobility contact layer 104 is within an appropriate range helps optimize the device's performance.

[0032] The energy progression of covalent bonds in different regions helps improve the stability and reliability of devices. By controlling this relationship, inhomogeneities in the device can be reduced, thereby enhancing its stability and reliability.

[0033] Among them, the longitudinal sound velocity of the quantum well 102 well layer is less than or equal to the longitudinal sound velocity of the high electron mobility contact layer 104 and less than or equal to the longitudinal sound velocity of the p-type semiconductor 103.

[0034] The well layer of the quantum well 102 is typically designed to have a low longitudinal sound velocity, while the longitudinal sound velocity of the high electron mobility contact layer 104 is between that of the p-type semiconductor 103 and the quantum well 102. This hierarchical design of sound velocities optimizes device performance, modulates the phonon transport characteristics within the device, and improves its stability and reliability. This design principle is of great significance in semiconductor devices, contributing to improved overall device performance and application effectiveness.

[0035] Furthermore, the p-type doping element of the high electron mobility contact layer 104 is any one or any combination of elements such as Mg, Zn, Li, Na, and K; the thickness of the high electron mobility contact layer 104 is 5 to 500 angstroms.

[0036] Furthermore, the quantum well 102 includes a first quantum well 102 and a second quantum well 102; the quantum well 102 is any one or any combination of GaN, InGaN, InN, AlInN, AlN, AlInGaN, AlGaN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, InGaP, SiC, Ga2O3, BN, and diamond; the well layer thickness of the quantum well 102 is 5 to 200 angstroms, and the barrier layer thickness is 10 to 500 angstroms.

[0037] Furthermore, the n-type semiconductor 101 is any one or any combination of GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, Ga2O3, BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, and InGaP; the thickness of the n-type semiconductor 101 is 50 to 90,000 angstroms.

[0038] Furthermore, the p-type semiconductor 103 is any one or any combination of GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, Ga2O3, BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, and InGaP; the thickness of the p-type semiconductor 103 is 10 to 80,000 angstroms.

[0039] Furthermore, the substrate 100 includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, Mo, diamond, Cu, TiW, InP, sapphire / SiO2 / SiN. x Composite substrate, sapphire / SiN x / SiO2 composite substrate, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiN x Any one of the following composite substrates: magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2, and LiGaO2.

[0040] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. An epitaxial structure for a group III nitride semiconductor light-emitting element, comprising, from bottom to top, a substrate, an n-type semiconductor, a quantum well, and a p-type semiconductor, characterized in that, The p-type semiconductor has a high electron mobility contact layer above it; the downward angle of the peak position of the peak electron drift velocity of the high electron mobility contact layer towards the quantum well is φ, the upward angle of the valley position of the peak velocity electric field of the high electron mobility contact layer towards the quantum well is β, the upward angle of the valley position of the hole mobility of the high electron mobility contact layer towards the quantum well is γ, and the upward angle of the valley position of the longitudinal sound velocity of the high electron mobility contact layer towards the quantum well is θ, where: 3°≤θ≤30°≤φ≤45°≤β≤60°≤γ≤87°, and the angles are the tangent tilt angles along the curve; the peak electron drift velocity of the p-type semiconductor ≤ the peak electron drift velocity of the high electron mobility contact layer ≤ the peak electron drift velocity of the quantum well layer; the covalent bond energy of the quantum well layer ≤ the covalent bond energy of the high electron mobility contact layer ≤ the covalent bond energy of the p-type semiconductor; the longitudinal sound velocity of the quantum well layer ≤ the longitudinal sound velocity of the high electron mobility contact layer ≤ the longitudinal sound velocity of the p-type semiconductor.

2. The epitaxial structure of a group III nitride semiconductor light-emitting element according to claim 1, characterized in that, The high electron mobility contact layer is any one or any combination of GaN, AlInGaN, AlGaN, InGaN, AlN, InN, and AlInN; the quantum well is a periodic structure composed of a well layer and a barrier layer, with a period number of 1 to 50.

3. The epitaxial structure of a group III nitride semiconductor light-emitting element according to claim 2, characterized in that, The peak electron drift velocity distribution, peak velocity electric field distribution, covalent bond energy distribution, and longitudinal sound velocity distribution of the high electron mobility contact layer all exhibit a V-shaped distribution.

4. The epitaxial structure of a group III nitride semiconductor light-emitting element according to claim 3, characterized in that, The p-type doping element of the high electron mobility contact layer is any one or any combination of elements such as Mg, Zn, Li, Na, and K; the thickness of the high electron mobility contact layer is 5 to 500 angstroms.

5. The epitaxial structure of a group III nitride semiconductor light-emitting element according to claim 4, characterized in that, The quantum well includes a first quantum well and a second quantum well; the quantum well is any one or any combination of GaN, InGaN, InN, AlInN, AlN, AlInGaN, AlGaN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, InGaP, SiC, Ga2O3, BN, and diamond; the thickness of the quantum well layer is 5 to 200 angstroms, and the thickness of the barrier layer is 10 to 500 angstroms.

6. The epitaxial structure of a group III nitride semiconductor light-emitting element according to claim 5, characterized in that, The n-type semiconductor is any one or any combination of GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, Ga2O3, BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, and InGaP; the thickness of the n-type semiconductor is 50 to 90,000 angstroms.

7. The epitaxial structure of a group III nitride semiconductor light-emitting element according to claim 6, characterized in that, The p-type semiconductor is any one or any combination of GaN, AlGaN, InGaN, AlInGaN, AlN, InN, AlInN, SiC, Ga2O3, BN, GaAs, GaP, InP, AlGaAs, AlInGaAs, AlGaInP, InGaAs, AlInAs, AlInP, AlGaP, and InGaP; the thickness of the p-type semiconductor is 10 to 80,000 angstroms.

8. The epitaxial structure of a group III nitride semiconductor light-emitting element according to any one of claims 1-7, characterized in that, The substrate includes sapphire, silicon, Ge, SiC, AlN, GaN, GaAs, Mo, diamond, Cu, TiW, InP, and sapphire / SiO2 / SiN. x Composite substrate, sapphire / SiN x / SiO2 composite substrate, sapphire / SiO2 composite substrate, sapphire / AlN composite substrate, sapphire / SiN x Any one of the following composite substrates: magnesium aluminum spinel MgAl2O4, MgO, ZnO, ZrB2, LiAlO2, and LiGaO2.

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