Semiconductor light emitting element and method of manufacturing

Abstract

This application provides a semiconductor light-emitting element and its fabrication method. The semiconductor light-emitting element includes a substrate; a multi-quantum-well light-emitting layer deposited on the substrate; a first electron blocking layer, a first hole accelerating layer, and a first hole providing layer sequentially deposited on the multi-quantum-well light-emitting layer, wherein the In content of the first hole accelerating layer is the same or gradually increases from the side near the first electron blocking layer to the side near the first hole providing layer; and a second electron blocking layer, a second hole accelerating layer, and a second hole providing layer sequentially deposited on the first hole providing layer, wherein the In content of the second hole accelerating layer is the same or gradually increases from the side near the second electron blocking layer to the side near the second hole providing layer. By controlling the In content in InGaN, the barrier height of InGaN can be controlled, which can effectively improve the hole injection efficiency, improve the recombination efficiency of electrons and holes in the multi-quantum-well light-emitting layer, and ultimately improve the light-emitting effect of the semiconductor light-emitting element.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to a semiconductor light-emitting element and its fabrication method. Background Technology

[0002] A light-emitting diode (LED) is a semiconductor electronic component that emits light. As a highly efficient, environmentally friendly, and green new solid-state lighting source, LEDs are a promising next-generation light source and are being rapidly and widely used in fields such as traffic lights, automotive interior and exterior lights, urban landscape lighting, indoor and outdoor displays, and small-pitch displays.

[0003] Epitaxial wafers are semiconductor thin films grown on single-crystal materials with matching crystal structures. After depositing an ohmic contact layer on the semiconductor thin film, a complete epitaxial structure can be formed. Processing the epitaxial wafer yields a chip, which, when packaged, becomes a light-emitting diode (LED). In the traditional process of preparing semiconductor thin films, the hole mobility is lower than the electron mobility, often making it more difficult for holes to be injected into the light-emitting region compared to electrons.

[0004] In related technologies, annealing processes are used to enhance hole activity and improve hole injection efficiency, but compared with electron migration, hole migration efficiency has not been significantly improved.

[0005] For the reasons mentioned above, there is an urgent need for a semiconductor light-emitting element that can effectively improve the hole injection efficiency and enhance the light-emitting effect of the semiconductor element. Summary of the Invention

[0006] This application provides a semiconductor light-emitting element and its fabrication method to solve the problem of low hole injection efficiency.

[0007] The first aspect of this application provides a semiconductor light-emitting element, comprising: a substrate;

[0008] A multi-quantum-well light-emitting layer deposited on a substrate;

[0009] A first electron blocking layer, a first hole accelerating layer, and a first hole providing layer are sequentially deposited on a multi-quantum-well light-emitting layer, wherein the In component content of the first hole accelerating layer is the same or gradually increases from the side near the first electron blocking layer to the side near the first hole providing layer.

[0010] A second electron blocking layer, a second hole accelerating layer, and a second hole providing layer are sequentially deposited on the first hole providing layer, wherein the In component content of the second hole accelerating layer is the same or gradually increases from the side near the second electron blocking layer to the side near the second hole providing layer.

[0011] In some embodiments of this application, the first hole acceleration layer is an InN single-layer structure.

[0012] In some embodiments of this application, the first hole accelerating layer is a superlattice structure composed of InN and InGaN, and the In composition content of the first hole accelerating layer gradually increases from the side near the first electron blocking layer to the side near the first hole providing layer.

[0013] In some embodiments of this application, the first hole accelerating layer specifically includes a first GaN structure, a first InGaN structure, and a first InN structure deposited sequentially along the direction from the first electron blocking layer to the first hole providing layer.

[0014] In some embodiments of this application, the first InGaN structure includes a first InGaN (In-gradient)1 structure, a first InxGa(1-x)N structure, a first InGaN (In-gradient)2 structure, a first InyGa(1-y)N structure, and a first InGaN (In-gradient)3 structure deposited sequentially along the direction from the first GaN structure to the first InN structure; wherein:

[0015] In the first InGaN (In graded) 1 structure, the In component content gradually increases along the direction from the first GaN structure to the first InN structure, and is less than or equal to 5%.

[0016] In the first InxGa(1-x)N structure, x is the doping concentration of In, 1-x represents the doping concentration of Ga, and x is greater than 0 and less than or equal to 0.05.

[0017] In the first InGaN (In graded)2 structure, the In component content gradually increases along the direction from the first GaN structure to the first InN structure, and is greater than 5% and less than or equal to 15%.

[0018] In the first InyGa(1-y)N structure, y is the doping concentration of In, 1-y represents the doping concentration of Ga, and y is greater than 0.05 and less than or equal to 0.15.

[0019] In the first InGaN (In graded)3 structure, the In component content gradually increases along the direction from the first GaN structure to the first InN structure, and is greater than 15% and less than or equal to 20%.

[0020] In some embodiments of this application, the second hole acceleration layer is an InN single-layer structure.

[0021] In some embodiments of this application, the second hole accelerating layer is a superlattice structure composed of InN and InGaN, and the In composition content of the second hole accelerating layer gradually increases from the side near the second electron blocking layer to the side near the second hole providing layer.

[0022] In some embodiments of this application, the second hole accelerating layer includes a second GaN structure, a second InGaN structure, and a second InN structure deposited sequentially along the direction from the second electron blocking layer to the second hole providing layer.

[0023] In some embodiments of this application, the second InGaN structure is a second InGaN (In-gradient)1 structure, a second InxGa(1-x)N structure, a second InGaN (In-gradient)2 structure, a second InyGa(1-y)N structure, and a second InGaN (In-gradient)3 structure deposited sequentially along the direction from the second GaN structure to the second InN structure; wherein:

[0024] In the second InGaN (In graded) 1 structure, the In component content gradually increases along the direction from the second GaN structure to the second InN structure, and is less than or equal to 5%.

[0025] In the second InxGa(1-x)N structure, x is the doping concentration of In, 1-x represents the doping concentration of Ga, and x is greater than 0 and less than or equal to 0.05.

[0026] In the second InGaN (In graded)2 structure, the In component content gradually increases along the direction from the second GaN structure to the second InN structure, and is greater than 5% and less than or equal to 15%.

[0027] In the second InyGa(1-y)N structure, y represents the doping concentration of In, 1-y represents the doping concentration of Ga, and y is greater than 0.05 and less than or equal to 0.15.

[0028] In the second InGaN (In graded)3 structure, the In component content gradually increases along the direction from the second GaN structure to the second InN structure, and is greater than 15% and less than or equal to 20%.

[0029] The second aspect of this application provides a method for fabricating a semiconductor light-emitting element, used to fabricate the semiconductor light-emitting element provided in the first aspect, the method comprising:

[0030] Provide a substrate;

[0031] Deposit a multi-quantum-well light-emitting layer on a substrate;

[0032] A first electron blocking layer, a first hole accelerating layer, and a first hole providing layer are sequentially deposited on a multi-quantum well light-emitting layer, wherein the In composition content of the first hole accelerating layer is the same or gradually increases from the side near the first electron blocking layer to the side near the first hole providing layer.

[0033] A second electron blocking layer, a second hole accelerating layer, and a second hole providing layer are sequentially deposited on the first hole providing layer, wherein the In component content of the second hole accelerating layer is the same or gradually increases from the side near the second electron blocking layer to the side near the second hole providing layer.

[0034] The beneficial technical effects of this application are:

[0035] A first electron blocking layer, a first hole accelerating layer, a first hole providing layer, a second electron blocking layer, a second hole accelerating layer, and a second hole providing layer are sequentially deposited on a multi-quantum-well light-emitting layer. Specifically, the main function of the first and second hole providing layers is to provide holes. The holes pass through the InN layer with the lowest potential barrier, and then through the InGaN layer, whose potential barrier height is controlled by the In composition content. This achieves a hole accelerating layer where the potential barrier decreases from the side near the electron blocking layer to the side near the hole providing layer. Because the InN layer has the lowest potential barrier, it forms a low electrostatic field, which can effectively collect holes. The holes then pass through the steep potential barrier of the InGaN with varying In composition content, which can effectively improve the efficiency of hole injection into the multi-quantum-well light-emitting layer, improve the recombination efficiency of electrons and holes in the multi-quantum-well light-emitting layer, and ultimately improve the light-emitting effect of the semiconductor light-emitting device. Attached Figure Description

[0036] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of a semiconductor light-emitting element in an epitaxial structure.

[0038] Figure 2 This is a schematic diagram showing the magnitude of the electrostatic field in each layer of the semiconductor light-emitting element in the embodiments of this application;

[0039] Figure 3 This is a schematic diagram of the fabrication process of the semiconductor light-emitting element in the embodiments of this application. Detailed Implementation

[0040] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application. They are merely examples of systems and methods consistent with some aspects of this application as detailed in the claims.

[0041] To facilitate understanding of the technical solution of this application, some concepts involved in the embodiments of this application will be explained first below.

[0042] A hole, also known as an electron hole (EH), is a phenomenon in solid-state physics where an electron escapes from a covalent bond, leaving a vacancy. Specifically, some valence electrons in a covalent bond gain energy through thermal motion, thus breaking free from the bond's constraints and becoming free electrons, thereby creating a vacancy in the covalent bond.

[0043] Deposition refers to the process by which substances transported by a moving medium settle and accumulate in a suitable location due to changes in conditions.

[0044] A potential energy barrier (PEB) is a spatial region with higher potential energy than the surrounding area; it is a small region near an extreme point.

[0045] A superlattice structure refers to a multilayer film in which two different elements are grown alternately in thin layers ranging from a few nanometers to tens of nanometers and maintain a strict periodicity.

[0046] An electron-blocking layer (EBL) is a thin film that controls the flow of electrons in an LED (blocking reverse leakage current) and improves luminous efficiency.

[0047] When annealing is used to improve hole mobility during the fabrication of semiconductor light-emitting elements, the process is not only complex, but the fabrication effect is also not ideal. The hole mobility in the fabricated semiconductor light-emitting elements is still low and has not been significantly improved, resulting in a decrease in the luminous efficiency of the LED.

[0048] Based on the above reasons, this application proposes a semiconductor light-emitting element and its fabrication method. A first electron blocking layer, a first hole accelerating layer, a first hole providing layer, a second electron blocking layer, a second hole accelerating layer, and a second hole providing layer are sequentially deposited on a multi-quantum-well light-emitting layer. This improves hole mobility and effectively blocks electron migration, thereby enhancing the light-emitting effect of the semiconductor light-emitting element.

[0049] Figure 1 This is a schematic diagram of a semiconductor light-emitting element in an epitaxial structure.

[0050] See Figure 1 The semiconductor light-emitting element provided in this application includes a substrate, a multi-quantum-well light-emitting layer, a first electron blocking layer, a first hole accelerating layer, a first hole providing layer, a second electron blocking layer, a second hole accelerating layer, and a second hole providing layer. The semiconductor light-emitting element provided in this application can be a P-type semiconductor light-emitting element.

[0051] The substrate can be one of the following: sapphire Al2O3 substrate, sapphire Al2O3 and silicon dioxide SiO2 composite substrate, silicon Si substrate, boron nitride BN substrate and silicon carbide SiC substrate.

[0052] Multiple quantum well (MQW) light-emitting layers are deposited on the substrate. The MQW is the main light-emitting layer in a semiconductor light-emitting device; the higher the recombination efficiency of the MQW, the better the light-emitting effect of the semiconductor light-emitting device.

[0053] The first electron blocking layer is deposited on the multi-quantum-well light-emitting layer. The first electron blocking layer can prevent electron transitions, which is conducive to the recombination of electrons and holes in the multi-quantum-well light-emitting layer, thereby improving the luminous efficiency of the semiconductor light-emitting device.

[0054] The first hole acceleration layer is deposited on the first electron blocking layer. The first hole acceleration layer can increase the migration speed of holes.

[0055] The first hole-providing layer is deposited on the first hole-accelerating layer. The first hole-providing layer can provide holes.

[0056] Among them, from the side near the first electron blocking layer to the side near the first hole providing layer (i.e. Figure 1 In the direction from bottom to top, the indium (In) content of the first hole acceleration layer is the same or gradually increases.

[0057] Specifically, when the barrier of the first electron blocking layer is relatively low, a first hole accelerating layer with the same In content from the side near the first electron blocking layer to the side near the first hole providing layer is used to directly transition to the lowest barrier. When the barrier of the first electron blocking layer is not relatively low, a first hole accelerating layer with gradually increasing In content from the side near the first electron blocking layer to the side near the first hole providing layer is used to control the barrier size of the first hole accelerating layer by utilizing the change in In content.

[0058] Understandably, the higher the In content, the smaller the barrier of the first hole acceleration layer and the lower the electrostatic field, which is beneficial to improving the hole mobility.

[0059] The second electron blocking layer is deposited on the first hole providing layer. The second electron blocking layer can prevent electron migration, which is conducive to the recombination of electrons and holes in the multi-quantum-well light-emitting layer, thereby improving the luminous efficiency of the semiconductor light-emitting device.

[0060] A second hole-accelerating layer is deposited on top of the second electron-blocking layer. The second hole-accelerating layer can increase the migration speed of holes.

[0061] The second hole-providing layer is deposited on the second hole-accelerating layer. The second hole-providing layer can provide holes.

[0062] Among them, from the side near the second electron blocking layer to the side near the second hole providing layer (i.e. Figure 1 (From bottom to top) The In component content of the second hole acceleration layer is the same or gradually increases.

[0063] Specifically, when the barrier of the second electron blocking layer is relatively low, a second hole accelerating layer with the same In content from the side near the second electron blocking layer to the side near the second hole providing layer is used to directly transition to the lowest barrier. When the barrier of the second electron blocking layer is not relatively low, a second hole accelerating layer with gradually increasing In content from the side near the second electron blocking layer to the side near the second hole providing layer is used to control the barrier size of the second hole accelerating layer by utilizing the change in In content.

[0064] It is understandable that the higher the In content, the smaller the barrier of the second hole acceleration layer and the lower the electrostatic field, which is beneficial to improving the hole mobility.

[0065] In one embodiment, the first hole-accelerating layer can be an indium nitride (InN) monolayer structure.

[0066] In one embodiment, the first hole acceleration layer can be a superlattice structure composed of InN and InGaN. The superlattice structure can be a single-cycle structure formed by depositing InN and InGaN once, or a multi-cycle structure formed by depositing InN and InGaN multiple times.

[0067] For example, if the number of deposition cycles is 1, an InN layer and an InGaN layer can be deposited sequentially on the first electron barrier layer. If the number of deposition cycles is 2, an InN layer, an InGaN layer, an InN layer, and an InGaN layer can be deposited sequentially on the first electron barrier layer. If the number of deposition cycles is 3, an InN layer, an InGaN layer, an InN layer, an InGaN layer, an InN layer, and an InGaN layer can be deposited sequentially on the first electron barrier layer. And so on. The number of deposition cycles can be adjusted according to the actual situation, and this embodiment does not limit the number of cycles.

[0068] In one embodiment, the first hole acceleration layer may specifically include a first gallium nitride (GaN) structure, a first InGaN structure, and a first InN structure deposited sequentially from the side near the first electron blocking layer to the side near the first hole providing layer.

[0069] The first InGaN structure may include a first InGaN(In-gradient)1 structure, a first InxGa(1-x)N structure, a first InGaN(In-gradient)2 structure, a first InyGa(1-y)N structure, and a first InGaN(In-gradient)3 structure deposited sequentially along the direction from the first GaN structure to the first InN structure.

[0070] In the first InGaN (In-gradient) 1 structure, the In component content gradually increases along the direction from the first GaN structure to the first InN structure, and is less than or equal to 5%. In specific implementation, when depositing the first InGaN (In-gradient) 1 structure, the inflow rate of the In source can be controlled by a flow controller, thereby achieving a gradual increase in the In component content along the direction from the first GaN structure to the first InN structure.

[0071] In the first InxGa(1-x)N structure, x is greater than 0 and less than or equal to 0.05.

[0072] Where x represents the doping concentration of In in the first InxGa(1-x)N structure; 1-x represents the doping concentration of Ga in the first InxGa(1-x)N structure.

[0073] In the first InGaN (In-gradient)2 structure, the In content gradually increases along the direction from the first GaN structure to the first InN structure, and is greater than 5% and less than or equal to 15%. In specific implementation, when depositing the first InGaN (In-gradient)2 structure, the inflow rate of the In source can be controlled by a flow controller, thereby achieving a gradual increase in the In content along the direction from the first GaN structure to the first InN structure.

[0074] In the first InyGa(1-y)N structure, y is greater than 0.05 and less than or equal to 0.15.

[0075] Where y represents the In doping concentration in the first InyGa(1-y)N structure; 1-y represents the Ga doping concentration in the first InyGa(1-y)N structure.

[0076] In the first InGaN (In-gradient)3 structure, the In content gradually increases along the direction from the first GaN structure to the first InN structure, and is greater than 15% and less than or equal to 20%. In specific implementation, when depositing the first InGaN (In-gradient)3 structure, the inflow rate of the In source can be controlled by a flow controller, thereby achieving a gradual increase in the In content along the direction from the first GaN structure to the first InN structure.

[0077] In this application, by setting a first hole acceleration layer with a gradually increasing In content, the In content gradually increases from bottom to top, lowering the potential barrier. This improves hole mobility while reducing electron mobility. This allows electrons and holes to recombine in the multi-quantum well, resulting in luminescence and thus improving the luminous efficiency of the semiconductor light-emitting element.

[0078] It should be noted that the temperature for depositing the first hole acceleration layer is between 700 and 1000°C. For example, the temperature used for deposition can be 700°C, 750°C, 800°C, 850°C, 900°C, 950°C, or 1000°C, or other temperature values ​​not shown between 700 and 1000°C.

[0079] Preferably, the deposition temperature is 700–800°C. The specific temperature value can be adjusted accordingly at different stages of the actual work. It should not be understood that a certain temperature must be maintained from the beginning to the end of the deposition of the first cavity acceleration layer. Instead, the temperature can be adjusted within a reasonable range, such as to a temperature range or value between 700–800°C or 850–1000°C.

[0080] It should be noted that the deposition thickness of the first hole acceleration layer is between 5 and 200 Å.

[0081] Preferably, the deposition thickness of the first hole acceleration layer is between 10 and 20 Å. If the deposition is too thick, it will affect the light emission effect of the semiconductor light-emitting element; if the deposition is too thin, it will affect the hole injection effect.

[0082] In one embodiment, the first hole acceleration layer can be a magnesium-passing P-type doped layer (a magnesium-passing hole transport layer).

[0083] In one embodiment, the second hole-accelerating layer can be an indium nitride (InN) monolayer structure.

[0084] In one embodiment, the second hole acceleration layer can be an InN or InGaN superlattice structure. The superlattice structure can be a single-cycle structure formed by InN or InGaN deposition in one step, or a multi-cycle structure formed by InN or InGaN deposition in multiple steps.

[0085] For example, if the number of deposition cycles is 1, an InN layer and an InGaN layer can be deposited sequentially on the second electron barrier layer. If the number of deposition cycles is 2, an InN layer, an InGaN layer, an InN layer, and an InGaN layer can be deposited sequentially on the second electron barrier layer. If the number of deposition cycles is 3, an InN layer, an InGaN layer, an InN layer, an InGaN layer, an InN layer, and an InGaN layer can be deposited sequentially on the second electron barrier layer. And so on. The number of deposition cycles can be adjusted according to the actual situation, and this embodiment does not limit the number of cycles.

[0086] Specifically, the second hole acceleration layer may include a second gallium nitride (GaN) structure, a second InGaN structure, and a second InN structure deposited sequentially from the side near the second electron blocking layer to the side near the second hole providing layer.

[0087] The second InGaN structure may include a second InGaN(In-gradient)1 structure, a second InxGa(1-x)N structure, a second InGaN(In-gradient)2 structure, a second InyGa(1-y)N structure, and a second InGaN(In-gradient)3 structure deposited sequentially along the direction from the second GaN structure to the second InN structure.

[0088] In the second InGaN (In-gradient) 1 structure, the In content gradually increases along the direction from the second GaN structure to the second InN structure, and is less than or equal to 5%. In specific implementation, when depositing the second InGaN (In-gradient) 1 structure, the inflow rate of the In source can be controlled by a flow controller, thereby achieving a gradual increase in the In content along the direction from the second GaN structure to the second InN structure.

[0089] In the second InxGa(1-x)N structure, x is greater than 0 and less than or equal to 0.05.

[0090] Where x represents the doping concentration of In in the second InxGa(1-x)N structure; 1-x represents the doping concentration of Ga in the second InxGa(1-x)N structure.

[0091] In the second InGaN (In-gradient)2 structure, the In content gradually increases along the direction from the second GaN structure to the second InN structure, and is greater than 5% and less than or equal to 15%. In specific implementation, when depositing the second InGaN (In-gradient)2 structure, the inflow rate of the In source is controlled by a flow controller to achieve a gradual increase in the In content along the direction from the second GaN structure to the second InN structure.

[0092] In the second InyGa(1-y)N structure, y is greater than 0.05 and less than or equal to 0.15.

[0093] Where y represents the In doping concentration in the second InyGa(1-y)N structure; 1-y represents the Ga doping concentration in the second InyGa(1-y)N structure.

[0094] In the second InGaN (In-gradient)3 structure, the In content gradually increases along the direction from the second GaN structure to the second InN structure, and is greater than 15% and less than or equal to 20%. In specific implementation, when depositing the second InGaN (In-gradient)3 structure, the inflow rate of the In source can be controlled by a flow controller, thereby achieving a gradual increase in the In content along the direction from the second GaN structure to the second InN structure.

[0095] In this application, by setting a second hole accelerating layer with a gradually increasing In content, the In content gradually increases from bottom to top, lowering the potential barrier. This improves hole mobility while reducing electron mobility. This allows electrons and holes to recombine in the multi-quantum well, resulting in luminescence and thus improving the luminous efficiency of the semiconductor light-emitting element.

[0096] It should be noted that the temperature for depositing the second hole acceleration layer is between 800 and 1100°C. For example, the temperature used for deposition can be 800°C, 850°C, 900°C, 950°C, 1000°C, 1050°C, or 1100°C, or other temperature values ​​not shown between 800 and 1100°C.

[0097] Preferably, the deposition temperature is 800–900°C. The specific temperature value can be adjusted accordingly at different stages of the actual work. It should not be understood that a single temperature must be maintained from the beginning to the end of the deposition of the second cavity acceleration layer. Instead, the temperature can be adjusted within a reasonable range, such as to a temperature range or value between 800–900°C or 950–1000°C.

[0098] It should be noted that the deposition thickness of the second hole acceleration layer is between 5 and 200 Å.

[0099] Preferably, the deposition thickness of the second hole acceleration layer is between 10 and 20 Å.

[0100] In one embodiment, the second hole acceleration layer can be a Mg-passing P-type doped layer (a magnesium-passing hole transport layer).

[0101] Figure 2 This is a schematic diagram showing the magnitude of the electrostatic field in each layer of the semiconductor light-emitting element in the embodiments of this application.

[0102] See Figure 2 The primary function of the first and second hole-accelerating layers is to accelerate hole injection. Specifically:

[0103] In the first hole accelerating layer, a first GaN structure, a first InGaN structure, and a first InN structure are deposited sequentially from the side closest to the first electron blocking layer to the side closest to the first hole providing layer. The first InN structure is connected to the first hole providing layer and has the lowest potential barrier, serving to receive holes provided by the first hole providing layer. The first GaN structure has the highest potential barrier and is connected to the first electron blocking layer. The first InGaN structure in the middle forms a steep potential barrier due to the varying In composition. Thus, the first hole accelerating layer can form a stepped decreasing electric field from the side closest to the first electron blocking layer to the side closest to the first hole providing layer.

[0104] Similarly, in the second hole acceleration layer, from the side near the second electron blocking layer to the side near the second hole providing layer, there are sequentially deposited second GaN structures, second InGaN structures, and second InN structures. The second InN structure is connected to the second hole providing layer and has the lowest potential barrier, used to receive holes provided by the second hole providing layer. The second GaN structure has the highest potential barrier and is connected to the second electron blocking layer. The second InGaN structure in the middle forms a steep potential barrier due to the unequal In composition. In this way, the second hole acceleration layer can also form a stepped decreasing electric field from the side near the second electron blocking layer to the side near the second hole providing layer.

[0105] In this way, both the first and second hole acceleration layers can form a stepped-decreasing electric field, thereby effectively improving the efficiency of hole injection into the multi-quantum-well light-emitting layer, improving the recombination efficiency of electrons and holes in the multi-quantum-well light-emitting layer, and ultimately improving the luminous efficiency of the semiconductor light-emitting element.

[0106] In one embodiment, the first electron blocking layer may be an aluminum nitride (AlN), gallium nitride (AlGaN), gallium indium (AlInGaN), InGaN monolayer structure or a superlattice structure combining at least two of these.

[0107] Superlattice structures can be composed of AlN and AlGaN, AlGaN and AlInGaN, AlInGaN and InGaN, AlN, AlGaN and AlInGaN, AlN, AlGaN and AlInGaN, AlN, AlGaN, AlInGaN and InGaN, etc.

[0108] A superlattice structure can be a single-cycle structure formed by the deposition of its components once, or a multi-cycle structure formed by the deposition of its components multiple times.

[0109] Preferably, the first electron blocking layer is a superlattice structure composed of AlN and AlGaN, the superlattice structure is a single cycle, and the AlGaN layer is deposited on the AlN layer.

[0110] During the deposition of the AlGaN layer, the flow rate of the Al source can be controlled by a flow controller, which can achieve a gradual decrease in the Al content from the side closer to the AlN layer to the side farther away from the AlN layer (from bottom to top).

[0111] It should be noted that the temperature for depositing the first electron blocking layer is between 700 and 1000°C. For example, the temperature used for deposition can be 700°C, 750°C, 800°C, 850°C, 900°C, 950°C, or 1000°C, or other temperature values ​​not shown between 700 and 1000°C.

[0112] Preferably, the deposition temperature is 800–900°C. The specific temperature value can be adjusted accordingly at different stages of the actual work. It should not be understood that a single temperature must be maintained from the beginning to the end of the deposition of the first electron blocking layer. Instead, the temperature can be adjusted within a reasonable range, such as to a temperature range or value between 700–800°C or 850–1000°C.

[0113] The temperature used to deposit the first electron blocking layer is carefully controlled to avoid damaging the material of the multi-quantum-well light-emitting layer due to excessive heat, while also avoiding excessively low temperatures that could affect the light emission performance. Therefore, the temperature for depositing the first electron blocking layer is controlled between 700 and 800°C, which effectively blocks electron migration without damaging the material of the multi-quantum-well light-emitting layer.

[0114] It should be noted that the deposition thickness of the first electron blocking layer is between 5 and 200 Å.

[0115] Preferably, the deposition thickness of the first electron blocking layer is between 20 and 40 Å.

[0116] In one embodiment, the first electron blocking layer may be an unintentionally doped layer.

[0117] In this embodiment, by depositing a first electron blocking layer on the multi-quantum-well light-emitting layer, electrons can be effectively blocked from migrating from the multi-quantum-well light-emitting layer, thus ensuring the luminous efficiency of the light-emitting element.

[0118] In one embodiment, the first hole-providing layer is a GaN, AlGaN, AlInGaN, InGaN monolayer structure or at least two combined superlattice structures.

[0119] The superlattice structure can be a superlattice structure composed of GaN and AlGaN, a superlattice structure composed of AlGaN and AlInGaN, a superlattice structure composed of AlInGaN and InGaN, a superlattice structure composed of GaN, AlGaN and AlInGaN, a superlattice structure composed of AlGaN, AlInGaN and InGaN, or a superlattice structure composed of GaN, AlGaN, AlInGaN and InGaN.

[0120] Superlattice structures can be single-cycle structures or multiple-cycle structures formed by multiple cycles.

[0121] Preferably, the first hole-providing layer is an AlInGaN monolayer structure.

[0122] During the deposition of AlInGaN monolayer structures, by controlling the inflow of Al and In sources using a flow controller, a potential barrier higher than that of the multi-quantum-well light-emitting layer can be achieved, thereby forming an electrostatic field higher than that of the multi-quantum-well light-emitting layer.

[0123] It should be noted that the temperature for depositing the first cavity providing the layer is between 700 and 1000°C. For example, the temperature used for deposition can be 700°C, 750°C, 800°C, 850°C, 900°C, 950°C, or 1000°C, or other temperature values ​​not shown between 700 and 1000°C.

[0124] Preferably, the deposition temperature is 700–800°C. The specific temperature value can be adjusted accordingly at different stages of the actual work. It should not be understood that a single temperature must be maintained from the beginning to the end of the deposition of the first cavity-providing layer. Rather, the temperature can be adjusted within a reasonable range, such as 700–800°C or 850–1000°C.

[0125] Since the first hole-providing layer, the first electron-blocking layer, and the first hole-accelerating layer are all structural layers close to the multi-quantum-well emitting layer, to avoid damaging the material of the multi-quantum-well emitting layer with high temperatures, and to avoid choosing a lower temperature which would affect the luminescence effect, the deposition temperature of the first hole-providing layer is controlled between 700 and 1000°C. This effectively blocks electron migration without damaging the material of the multi-quantum-well emitting layer.

[0126] In some embodiments, the second electron blocking layer is a single-layer structure of AlN, AlGaN, or AlInGaN, or a superlattice structure of at least two combinations of AlN, AlGaN, AlInGaN, InGaN, and GaN.

[0127] Superlattice structures can be composed of AlN and AlGaN, AlGaN and AlInGaN, InGaN and GaN, AlN, AlGaN and AlInGaN, AlGaN, AlInGaN and InGaN, AlInGaN, InGaN and GaN, AlInGaN, InGaN and GaN, AlInGaN, InGaN and GaN, AlN, AlGaN, AlInGaN and InGaN, AlGaN, AlInGaN and InGaN, AlGaN, AlInGaN, InGaN and GaN, and AlN, AlGaN, AlInGaN, InGaN and GaN, etc.

[0128] Superlattice structures can be single-cycle structures or multiple-cycle structures with multiple depositions.

[0129] Preferably, the second electron blocking layer is a superlattice structure composed of AlN and AlGaN, the superlattice structure is a single-cycle structure, and the AlGaN layer is deposited on the AlN layer.

[0130] During the deposition of the AlGaN layer, the flow rate of the Al source can be controlled by a flow controller, which can achieve a gradual decrease in the Al content from the side closer to the AlN layer to the side farther away from the AlN layer (from bottom to top).

[0131] It should be noted that the temperature for depositing the second electron blocking layer is between 800 and 1100°C. For example, the temperature used for deposition can be 800°C, 850°C, 900°C, 950°C, 1000°C, 1050°C, or 1100°C, or other temperature values ​​not shown between 800 and 1100°C.

[0132] Preferably, the deposition temperature is 900–1000°C. The specific temperature value can be adjusted accordingly at different stages of the actual work. It should not be understood that a single temperature must be maintained from the beginning to the end of the deposition of the second electron blocking layer. Instead, the temperature can be adjusted within a reasonable range, such as 800–900°C or 950–1100°C.

[0133] The deposition temperature for the second electron blocking layer is chosen to be between 800 and 1100℃. Compared to the first electron blocking layer, the deposition temperature is relatively higher. This is mainly because the deposition location of the second electron blocking layer is relatively far from the multi-quantum-well light-emitting layer, and the relatively higher temperature will not damage the material of the multi-quantum-well light-emitting layer. Therefore, controlling the deposition temperature of the second electron blocking layer between 800 and 1100℃ can effectively block electron migration without damaging the material of the multi-quantum-well light-emitting layer.

[0134] It should be noted that the deposition thickness of the second electron blocking layer is between 50 and 500 Å.

[0135] Preferably, the deposition thickness of the second electron blocking layer is between 100 and 200 Å.

[0136] In one embodiment, the second electron blocking layer may be an unintentionally doped layer, a Mg-passing or intermittently Mg-passing P-type doped layer.

[0137] Specifically, the function of the second electron blocking layer is to block the migration of electrons and reduce the electron mobility.

[0138] In one embodiment, the second hole provides a layer that is a GaN or InGaN monolayer, or a superlattice layer structure composed of GaN and magnesium nitride (MgN), or a superlattice layer structure composed of InGaN and MgN.

[0139] Superlattice structures can be single-cycle structures or multiple-cycle structures formed by multiple cycles.

[0140] Preferably, the second hole-providing layer is a GaN monolayer with a lower barrier than the first hole-providing layer.

[0141] It should be noted that the temperature for depositing the second cavity-providing layer is between 800 and 1100°C. Exemplarily, the deposition temperature can be 800°C, 850°C, 900°C, 950°C, 1000°C, 1050°C, or 1100°C, or other undisclosed temperature values ​​between 800 and 1100°C. Preferably, the temperature for depositing the second cavity-providing layer is between 900 and 1000°C.

[0142] It should be noted that the deposition thickness of the second cavity-providing layer can be between 30 and 500 Å.

[0143] Preferably, the deposition thickness of the second cavity providing layer can be between 50 and 100 Å.

[0144] In one embodiment, the second hole-providing layer can be a Mg-through or intermittently Mg-through P-type doped layer.

[0145] In some embodiments, the semiconductor light-emitting element further includes an unintentionally doped gallium nitride layer, an N-type gallium nitride layer, and a stress-relieving layer sequentially deposited on a substrate. The multi-quantum-well light-emitting layer is deposited on the stress-relieving layer.

[0146] Figure 3 This is a schematic diagram of the fabrication process of the semiconductor light-emitting element in the embodiments of this application.

[0147] See Figure 3 This application also provides a method for fabricating a semiconductor light-emitting element, used to fabricate the semiconductor light-emitting element in any of the above embodiments, the method comprising:

[0148] Step S100: Provide a substrate;

[0149] The substrate can be one of the following: sapphire Al2O3 substrate, sapphire Al2O3 and silicon dioxide SiO2 composite substrate, silicon Si substrate, boron nitride BN substrate and silicon carbide SiC substrate.

[0150] Step S200: Deposit a multi-quantum-well light-emitting layer on the substrate;

[0151] Step S300: Sequentially deposit a first electron blocking layer, a first hole accelerating layer, and a first hole providing layer on the multi-quantum well light-emitting layer, wherein the In component content in the first hole accelerating layer near the first electron blocking layer is the same or gradually increases from the side near the first electron blocking layer to the side near the first hole providing layer.

[0152] The deposition temperatures of the first electron blocking layer, the first hole accelerating layer, and the first hole providing layer can be between 700 and 1000°C. Specifically, the preferred deposition temperature for the first electron blocking layer is between 800 and 900°C, the preferred deposition temperature for the first hole accelerating layer is between 700 and 800°C, and the preferred deposition temperature for the first hole providing layer is between 700 and 800°C.

[0153] The thickness of the first electron blocking layer is 5–200 Å, preferably 20–40 Å. The first electron blocking layer can be an unintentionally doped layer.

[0154] The thickness of the first hole-accelerating layer is 5–200 Å, preferably 10–20 Å. The first hole-accelerating layer can be a through-hole Mg P-type doped layer.

[0155] The thickness of the first hole-providing layer is 100–500 Å, preferably 150–250 Å. The first hole-accelerating layer can be a Mg-passing or intermittently Mg-passing P-type doped layer.

[0156] Step S400: Sequentially deposit a second electron blocking layer, a second hole accelerating layer, and a second hole providing layer on the first hole providing layer, wherein the In component content in the second hole accelerating layer near the second electron blocking layer is the same or gradually increases from the side near the second electron blocking layer to the side near the second hole providing layer.

[0157] The deposition temperature of the second electron blocking layer, the second hole accelerating layer, and the second hole providing layer can be between 800 and 1100°C. The preferred deposition temperature of the second electron blocking layer is between 900 and 1000°C, the preferred deposition temperature of the second hole accelerating layer is between 800 and 900°C, and the preferred deposition temperature of the second hole providing layer is between 900 and 1000°C.

[0158] The thickness of the second electron blocking layer is 50-500 Å, preferably 100-200 Å. The second electron blocking layer is an unintentionally doped layer, a Mg-passed or intermittently Mg-passed P-type doped layer.

[0159] The thickness of the second hole acceleration layer is 5–200 Å, preferably 10–20 Å, and the second hole acceleration layer is a through-Mg P-type doped layer.

[0160] The thickness of the second hole-providing layer is 30–500 Å, preferably 50–100 Å, and the second hole-accelerating layer is a Mg-passing or intermittently Mg-passing P-type doped layer.

[0161] This application also provides an epitaxial structure, including the semiconductor light-emitting element in any of the above embodiments, and further including an ohmic contact layer deposited on the second hole-providing layer.

[0162] The beneficial technical effects of the embodiments of this application are as follows:

[0163] A first electron blocking layer, a first hole accelerating layer, a first hole providing layer, a second electron blocking layer, a second hole accelerating layer, and a second hole providing layer are sequentially deposited on a multi-quantum-well light-emitting layer. Specifically, the main function of the first and second hole providing layers is to provide holes. The holes pass through the InN layer with the lowest potential barrier, and then through the InGaN layer with a potential barrier height controlled by the In composition content, achieving a hole accelerating layer where the potential barrier decreases from the side near the electron blocking layer to the side near the hole providing layer. Because the InN layer has the lowest potential barrier, it forms a low electrostatic field, which can effectively collect holes. The holes then pass through the steep potential barrier of the InGaN with varying In composition content, which can effectively improve the efficiency of hole injection into the multi-quantum-well light-emitting layer, improve the recombination efficiency of electrons and holes in the multi-quantum-well light-emitting layer, and thus improve the luminous efficacy of the semiconductor light-emitting device.

[0164] Similar parts between the embodiments provided in this application can be referred to mutually. The specific implementation methods provided above are only a few examples under the overall concept of this application and do not constitute a limitation on the scope of protection of this application. For those skilled in the art, any other implementation methods extended from the solution of this application without creative effort shall fall within the scope of protection of this application.

Claims

1. A semiconductor light-emitting element, characterized in that, include: Substrate; A multi-quantum-well light-emitting layer deposited on the substrate; A first electron blocking layer, a first hole accelerating layer, and a first hole providing layer are sequentially deposited on the multi-quantum well light-emitting layer, wherein the In component content of the first hole accelerating layer gradually increases from the side closer to the first electron blocking layer to the side closer to the first hole providing layer. A second electron blocking layer, a second hole accelerating layer, and a second hole providing layer are sequentially deposited on the first hole providing layer, wherein the In component content of the second hole accelerating layer gradually increases from the side closer to the second electron blocking layer to the side closer to the second hole providing layer. The first hole acceleration layer includes a first GaN structure, a first InGaN structure, and a first InN structure deposited sequentially along the direction from the first electron blocking layer to the first hole providing layer; The first InGaN structure includes a first InGaN1 structure, a first InxGa(1-x)N structure, a first InGaN2 structure, a first InyGa(1-y)N structure, and a first InGaN3 structure deposited sequentially along the direction from the first GaN structure to the first InN structure; wherein: the In in the first InGaN1 structure, the first InGaN2 structure, and the first InGaN3 structure is gradient; The second hole accelerating layer includes a second GaN structure, a second InGaN structure, and a second InN structure deposited sequentially along the direction from the second electron blocking layer to the second hole providing layer; The second InGaN structure is a second InGaN1 structure, a second InxGa(1-x)N structure, a second InGaN2 structure, a second InyGa(1-y)N structure, and a second InGaN3 structure deposited sequentially along the direction from the second GaN structure to the second InN structure; wherein: the In in the second InGaN1 structure, the second InGaN2 structure, and the second InGaN3 structure is gradually changed.

2. The semiconductor light-emitting element according to claim 1, characterized in that, In the first InGaN1 structure, the In content gradually increases along the direction from the first GaN structure to the first InN structure, and is less than or equal to 5%; In the first InxGa(1-x)N structure, x is the doping concentration of In, 1-x represents the doping concentration of Ga, and x is greater than 0 and less than or equal to 0.

05. In the first InGaN2 structure, along the direction from the first GaN structure to the first InN structure, the In component content gradually increases, and is greater than 5% and less than or equal to 15%; In the first InyGa(1-y)N structure, y is the doping concentration of In, 1-y represents the doping concentration of Ga, and y is greater than 0.05 and less than or equal to 0.

15. In the first InGaN3 structure, along the direction from the first GaN structure to the first InN structure, the In component content gradually increases, and is greater than 15% and less than or equal to 20%.

3. The semiconductor light-emitting element according to claim 1, characterized in that, In the second InGaN1 structure, along the direction from the second GaN structure to the second InN structure, the In content gradually increases, and is less than or equal to 5%; In the second InxGa(1-x)N structure, x is the doping concentration of In, 1-x represents the doping concentration of Ga, and x is greater than 0 and less than or equal to 0.

05. In the second InGaN2 structure, along the direction from the second GaN structure to the second InN structure, the In component content gradually increases, and is greater than 5% and less than or equal to 15%; In the second InyGa(1-y)N structure, y is the doping concentration of In, 1-y represents the doping concentration of Ga, and y is greater than 0.05 and less than or equal to 0.

15. In the second InGaN3 structure, the In content gradually increases along the direction from the second GaN structure to the second InN structure, and is greater than 15% and less than or equal to 20%.

4. A method for fabricating a semiconductor light-emitting element, characterized in that, The method for preparing the semiconductor light-emitting element according to any one of claims 1-3 comprises: Provide a substrate; A multi-quantum-well light-emitting layer is deposited on the substrate; A first electron blocking layer, a first hole accelerating layer, and a first hole providing layer are sequentially deposited on the multi-quantum well light-emitting layer, wherein the In component content of the first hole accelerating layer gradually increases from the side closer to the first electron blocking layer to the side closer to the first hole providing layer. A second electron blocking layer, a second hole accelerating layer, and a second hole providing layer are sequentially deposited on the first hole providing layer, wherein the In component content of the second hole accelerating layer gradually increases from the side closer to the second electron blocking layer to the side closer to the second hole providing layer.

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