Light emitting diode and method of manufacturing the same

Abstract

The application discloses a light emitting diode and a preparation method thereof. The light emitting diode comprises a silicon substrate, a buffer layer, an unintentionally doped layer, a gallium nitride composite layer, a multi-quantum well light emitting layer, an electron blocking layer and a first gallium nitride layer which are stacked in sequence. The gallium nitride composite layer comprises a second gallium nitride layer with a first doping concentration, an aluminum gallium nitride layer, a third gallium nitride layer with a second doping concentration and a fourth gallium nitride layer with a third doping concentration which are stacked in sequence. The first doping concentration is higher than the third doping concentration, and the third doping concentration is higher than the second doping concentration. The light emitting diode can effectively improve the crystal quality and electron migration of gallium nitride in the gallium nitride composite layer, reduce the leakage channel, and thus improve the anti-static capacity and reverse leakage capacity of the light emitting diode by optimizing the structure of the light emitting diode and limiting the doping gradient in the gallium nitride layer.

Description

Technical Field

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

[0002] Silicon is the most abundant element on Earth, and silicon electronic devices represent the most mature area of ​​the semiconductor industry. The high crystal quality, large size, low cost, and good thermal and electrical conductivity of silicon substrates have attracted researchers and manufacturers to invest in the research and production of gallium nitride (GaN) light-emitting diodes (LEDs) on silicon substrates. Furthermore, silicon substrate LEDs have the potential to realize silicon-based optoelectronic integration, and the conductivity of silicon substrates allows for the fabrication of high-quality HEMT devices. However, a large lattice mismatch exists between the silicon substrate and the epitaxial GaN layer, resulting in poorer epitaxial growth of GaN crystals and lower antistatic properties and reverse leakage current compared to LEDs on traditional sapphire substrates. Summary of the Invention

[0003] Therefore, in order to improve the antistatic properties and reverse leakage current capability of silicon substrate light-emitting diodes, it is necessary to provide a light-emitting diode and its fabrication method.

[0004] The present invention provides a light-emitting diode, comprising a silicon substrate, a buffer layer, an unintentionally doped layer, a gallium nitride composite layer, a multi-quantum-well light-emitting layer, an electron blocking layer, and a first gallium nitride layer stacked sequentially.

[0005] The gallium nitride composite layer comprises, in sequence, a second gallium nitride layer with a first doping concentration, an aluminum gallium nitride layer, a third gallium nitride layer with a second doping concentration, and a fourth gallium nitride layer with a third doping concentration, wherein the first doping concentration is higher than the third doping concentration, and the third doping concentration is higher than the second doping concentration.

[0006] The second gallium nitride layer, the third gallium nitride layer, and the fourth gallium nitride layer have a first conductivity type, and the electron blocking layer and the first gallium nitride layer have a second conductivity type, wherein the first conductivity type is opposite to the second conductivity type.

[0007] In one embodiment, the gallium nitride composite layer satisfies one or more of the following conditions:

[0008] (1) The first doping concentration is 8×10 19 / cm 3 ~4×10 19 / cm 3 ;

[0009] (2) The second doping concentration is 8×10 16 / cm 3 ~2×1018 / cm 3 ;

[0010] (3) The third doping concentration is 8×10 17 / cm 3 ~2×10 19 / cm 3 ;

[0011] (4) The thickness of the second gallium nitride layer is 0.5 μm to 2.5 μm;

[0012] (5) The thickness of the aluminum gallium nitride layer is 40nm to 120nm;

[0013] (6) The thickness of the third gallium nitride layer is 80nm to 520nm;

[0014] (7) The thickness of the fourth gallium nitride layer is 5nm to 120nm.

[0015] In one embodiment, the buffer layer satisfies one or more of the following conditions:

[0016] (1) The material of the buffer layer is selected from at least one of gallium nitride, aluminum gallium nitride, indium aluminum gallium nitride, and indium gallium nitride;

[0017] (2) The thickness of the buffer layer is 200nm to 1100nm.

[0018] In one embodiment, the unintentionally doped layer satisfies one or more of the following conditions:

[0019] (1) The material of the unintentionally doped layer is gallium nitride;

[0020] (2) The thickness of the unintentionally doped layer is 0.2 μm to 1.2 μm.

[0021] In one embodiment, the multi-quantum-well light-emitting layer includes n stacked base layers, each base layer including stacked barrier layers and potential well layers, the barrier layers being in contact with the gallium nitride composite layer, where n is an integer from 3 to 12.

[0022] In one embodiment, the multi-quantum-well light-emitting layer satisfies one or more of the following conditions:

[0023] (1) The material of the barrier layer is Al x Ga 1-x N, where x is 0 to 0.5;

[0024] (2) The material of the potential well layer is In y Ga 1-y N, where y is 0 to 0.4;

[0025] (3) The thickness of the barrier layer is 2nm to 12nm;

[0026] (4) The thickness of the potential well layer is 1 nm to 6 nm.

[0027] In one embodiment, the electron blocking layer satisfies one or more of the following conditions:

[0028] (1) The material of the electron blocking layer is selected from one or more of gallium nitride, aluminum gallium nitride, indium aluminum gallium nitride, and aluminum nitride;

[0029] (2) The thickness of the electron blocking layer is 20nm to 90nm;

[0030] (3) The doping concentration of the electron blocking layer is 10 18 / cm 3 ~5×10 19 / cm 3 .

[0031] In one embodiment, the first gallium nitride layer satisfies one or more of the following conditions:

[0032] (1) The thickness of the first gallium nitride layer is 20nm to 170nm;

[0033] (2) The doping concentration of the first gallium nitride layer is 10 18 / cm 3 ~5×10 20 / cm 3 .

[0034] The present invention also provides a method for fabricating the above-mentioned light-emitting diode, wherein the buffer layer, the unintentionally doped layer, the gallium nitride composite layer, the multi-quantum-well light-emitting layer, the electron blocking layer and the first gallium nitride layer are sequentially formed on the silicon substrate.

[0035] In one embodiment, the above preparation method satisfies one or more of the following conditions:

[0036] (1) The conditions for the formation of the buffer layer include: a growth temperature of 750℃~1100℃;

[0037] (2) The conditions for the formation of the unintentionally doped layer include: a growth temperature of 950℃~1300℃;

[0038] (3) The conditions for forming the gallium nitride composite layer include: a growth temperature of 800℃~1200℃ and a growth pressure of 30 torr~250 torr;

[0039] (4) The conditions for forming the multi-quantum well light-emitting layer include: a growth temperature of 600℃~1100℃;

[0040] (5) The conditions for the formation of the electron blocking layer include: a growth temperature of 800℃~1200℃;

[0041] (6) The conditions for forming the first gallium nitride layer include: a growth temperature of 800℃~1200℃.

[0042] In the above-mentioned light-emitting diode structure, gallium nitride crystals are epitaxially grown. By setting a gallium nitride composite layer including a second gallium nitride layer with a first doping concentration, an aluminum gallium nitride layer, a third gallium nitride layer with a second doping concentration, and a fourth gallium nitride layer with a third doping concentration stacked sequentially, and defining the doping gradient in the gallium nitride layer, the crystal quality and electron migration of gallium nitride in the gallium nitride composite layer can be effectively improved, and leakage channels can be reduced, thereby improving the antistatic capability and reverse leakage capability of the light-emitting diode. Attached Figure Description

[0043] Figure 1 This is a diagram of the structure of a light-emitting diode (LED).

[0044] Figure reference numerals: 10: Light-emitting diode, 100: Silicon substrate, 110: Buffer layer, 120: Unintentionally doped layer, 130: Gallium nitride composite layer, 131: Second gallium nitride layer, 132: Aluminum gallium nitride layer, 133: Third gallium nitride layer, 134: Fourth gallium nitride layer, 140: Multi-quantum well light-emitting layer, 141: Barrier layer, 142: Potential well layer, 150: Electron blocking layer, 160: First gallium nitride layer. Detailed Implementation

[0045] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of the invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. In the description of the present invention, "a number" means at least one, such as one, two, etc., unless otherwise explicitly specified.

[0047] The terms "preferred," "more preferably," etc., used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0048] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0049] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as the second element, component, area, layer, or portion.

[0050] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0051] When using “including,” “having,” and “contains” as described herein, the intention is to cover non-exclusive inclusion, unless an explicit qualifying term such as “only,” “consisting of,” etc., is used, in which case another component may be added.

[0052] Unless otherwise stated, a singular term may include a plural term and should not be understood as having a quantity of one.

[0053] Furthermore, the accompanying drawings are not drawn to a 1:1 scale, and the relative dimensions of the elements are shown in the drawings only as examples to facilitate understanding of the invention, but are not necessarily drawn to actual scale. The scale in the drawings does not constitute a limitation on the invention. It should be noted that when a component is referred to as "on another component," "connected to another component," "coupled to another component," or "in contact with another component," it can be directly on, connected to, coupled to, or in contact with that other component, or there may be an inserting component. In contrast, when a component is referred to as "directly on another component," "directly connected to," "directly coupled to," or "directly in contact with" another component, there is no inserting component. Similarly, when the first component is referred to as "electrically contacting" or "electrically coupling" to the second component, there is an electrical path between the first and second components that allows current to flow. This electrical path may include capacitors, coupled inductors, and / or other components that allow current to flow, even without direct contact between the conductive components.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0055] like Figure 1 The present invention provides a light-emitting diode 10, which includes a silicon substrate 100, a buffer layer 110, an unintentionally doped layer 120, a gallium nitride composite layer 130, a multi-quantum-well light-emitting layer 140, an electron blocking layer 150 and a first gallium nitride layer 160 stacked sequentially.

[0056] The gallium nitride composite layer 130 includes a second gallium nitride layer 131 with a first doping concentration, an aluminum gallium nitride layer 132, a third gallium nitride layer 133 with a second doping concentration, and a fourth gallium nitride layer 134 with a third doping concentration, which are stacked sequentially. The first doping concentration is higher than the third doping concentration, and the third doping concentration is higher than the second doping concentration.

[0057] The second gallium nitride layer 131, the third gallium nitride layer 133, and the fourth gallium nitride layer 134 have a first conductivity type, and the electron blocking layer 150 and the first gallium nitride layer 160 have a second conductivity type. The first conductivity type is the opposite of the second conductivity type.

[0058] Understandably, if the first conductivity type is N-type, then the second conductivity type is P-type, and if the first conductivity type is P-type, then the second conductivity type is N-type.

[0059] In a specific example, the first doping concentration in the gallium nitride composite layer 130 is 8 × 10⁻⁶. 19 / cm 3 ~4×10 19 / cm 3 Preferably, the first doping concentration is 10. 19 / cm 3 ~2×10 19 / cm 3 Specifically, the first doping concentration can be, but is not limited to, 10. 19 / cm 3 1.1×10 19 / cm 3 1.2×10 19 / cm 3 1.3×10 19 / cm 3 1.4×10 19 / cm 3 1.5×10 19 / cm 3 1.6×10 19 / cm 3 1.7×10 19 / cm 3 1.8×10 19 / cm 3 1.9×10 19 / cm 3 Or 2×10 19 / cm 3 .

[0060] In one specific example, the thickness of the second gallium nitride layer 131 in the gallium nitride composite layer 130 is 0.5 μm to 2.5 μm. Further, the thickness of the second gallium nitride layer 131 is 1 μm to 2 μm, and the thickness of the second gallium nitride layer 131 can be, but is not limited to, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, or 2 μm.

[0061] In a specific example, the second doping concentration in the gallium nitride composite layer 130 is 8 × 10⁻⁶.16 / cm 3 ~2×10 18 / cm 3 Preferably, the second doping concentration is 10. 17 / cm 3 ~10 18 / cm 3 Specifically, the second doping concentration can be, but is not limited to, 10. 17 / cm 3 2×10 17 / cm 3 3×10 17 / cm 3 4×10 17 / cm 3 5×10 17 / cm 3 6×10 17 / cm 3 7×10 17 / cm 3 8×10 17 / cm 3 9×10 17 / cm 3 Or 10 18 / cm 3 .

[0062] In a specific example, the thickness of the third gallium nitride layer 133 in the gallium nitride composite layer 130 is 80 nm to 520 nm. Preferably, the thickness of the third gallium nitride layer 133 is 100 nm to 500 nm. Specifically, the thickness of the third gallium nitride layer 133 can be, but is not limited to, 100 nm, 200 nm, 300 nm, 400 nm, or 500 nm.

[0063] In a specific example, the third doping concentration in the gallium nitride composite layer 130 is 8 × 10⁻⁶. 17 / cm 3 ~2×10 19 / cm 3 Preferably, the third doping concentration is 10. 18 / cm 3 ~10 19 / cm 3 Specifically, the third doping concentration can be, but is not limited to, 10. 18 / cm 3 2×10 18 / cm 3 3×10 18 / cm 3 4×10 18 / cm 3 5×1018 / cm 3 6×10 18 / cm 3 7×10 18 / cm 3 8×10 18 / cm 3 9×10 18 / cm 3 Or 10 19 / cm 3 .

[0064] In one specific example, the thickness of the fourth gallium nitride layer 134 in the gallium nitride composite layer 130 is 5 nm to 120 nm. In a preferred example, the thickness of the fourth gallium nitride layer 134 is 10 nm to 100 nm. Specifically, the thickness of the fourth gallium nitride layer 134 can be, but is not limited to, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm.

[0065] Understandably, the doping elements in the second gallium nitride layer 131, the third gallium nitride layer 133, and the fourth gallium nitride layer 134 may be, but are not limited to, silicon.

[0066] In one specific example, the thickness of the aluminum gallium nitride (AlGaN) layer in the gallium nitride composite layer 130 is 40 nm to 120 nm. In a preferred example, the thickness of the aluminum gallium nitride (AlGaN) layer is 50 nm to 100 nm; specifically, the thickness of the aluminum gallium nitride (AlGaN) layer can be, but is not limited to, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm. Understandably, the molar ratio of Al to Ga in the aluminum gallium nitride layer 132 is 0.1 to 0.3.

[0067] In one specific example, the material of the buffer layer 110 is selected from at least one of gallium nitride (GaN), aluminum gallium nitride (AlGaN), indium aluminum gallium nitride (InAlGaN), and indium gallium nitride (InGaN).

[0068] In one specific example, the thickness of the buffer layer 110 is 200 nm to 1100 nm. In a preferred example, the thickness of the buffer layer 110 is 300 nm to 1000 nm. Specifically, the thickness of the buffer layer 110 may be, but is not limited to, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm or 1000 nm.

[0069] In one specific example, the material of the unintentionally doped layer 120 is gallium nitride.

[0070] In one specific example, the thickness of the unintentionally doped layer 120 is 0.2 μm to 1.2 μm. In a preferred example, the thickness of the unintentionally doped layer 120 is 0.5 μm to 1 μm. Specifically, the thickness of the unintentionally doped layer 120 may be, but is not limited to, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, or 1 μm.

[0071] In a specific example, the multi-quantum-well light-emitting layer 140 includes n stacked base layers, each base layer comprising stacked barrier layers 141 and potential well layers 142, where n is an integer from 3 to 12. Preferably, n is an integer from 5 to 12; specifically, n can be, but is not limited to, 5, 6, 7, 8, 9, or 10. Understandably, the number of barrier layers 141 is the same as the number of potential well layers 142.

[0072] In a specific example, the material of the barrier layer 141 in the multi-quantum-well emitting layer 140 is Al. x Ga 1-x N, where x is 0 to 0.5. Preferably, x is 0 to 0.4.

[0073] In a specific example, the material of the potential well layer 142 in the multi-quantum-well light-emitting layer 140 is In. y Ga 1-y N, where y is 0 to 0.4. Preferably, y is 0 to 0.3.

[0074] In a specific example, the thickness of the barrier layer 141 in the multi-quantum well light-emitting layer 140 is 2 nm to 12 nm. Further, the thickness of the barrier layer 141 is 3 nm to 10 nm. Specifically, the thickness of the barrier layer 141 can be, but is not limited to, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm.

[0075] In a specific example, the thickness of the potential well layer 142 in the multi-quantum-well light-emitting layer 140 is 1 nm to 6 nm. Further, the thickness of the potential well layer 142 is 2 nm to 4 nm; specifically, the thickness of the potential well layer 142 can be, but is not limited to, 2 nm, 3 nm, or 4 nm. Understandably, the thickness here refers to the thickness of the barrier layer 141 in a base layer or the thickness of the potential well layer 142 in a base layer.

[0076] In one specific example, the material of the electron blocking layer 150 is selected from one or more of gallium nitride (GaN), aluminum gallium nitride (AlGaN), indium aluminum gallium nitride (AlInGaN), and aluminum nitride (AlN).

[0077] Understandably, when the electron blocking layer 150 is made of multiple materials, it can also be a superlattice structure formed between multiple materials.

[0078] In one specific example, the thickness of the electron blocking layer 150 is 20 nm to 90 nm. In a preferred example, the thickness of the electron blocking layer 150 is 30 nm to 80 nm. Specifically, the thickness of the electron blocking layer 150 may be, but is not limited to, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, or 80 nm.

[0079] In one specific example, the electron blocking layer 150 has a doping concentration of 10. 18 / cm 3 ~5×10 19 / cm 3 Furthermore, the doping concentration of the electron blocking layer 150 is 5 × 10⁻⁶. 18 / cm 3 ~3.5×10 19 / cm 3 Specifically, the doping concentration of the electron blocking layer 150 can be, but is not limited to, 5 × 10⁻⁶. 18 / cm 3 6×10 18 / cm 3 7×10 18 / cm 3 8×10 18 / cm 3 9×10 18 / cm 3 10 19 1.5×10 19 / cm 3 2.5×10 19 / cm 3 Or 3.5×10 19 / cm 3 Understandably, the doping element in the electronically doped layer can be, but is not limited to, magnesium.

[0080] In one specific example, the thickness of the first gallium nitride layer 160 is 20 nm to 170 nm. Further, the thickness of the first gallium nitride layer 160 is 30 nm to 150 nm. Specifically, the thickness of the first gallium nitride layer 160 can be, but is not limited to, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, or 150 nm.

[0081] In one specific example, the doping concentration of the first gallium nitride layer 160 is 10. 18 / cm 3 ~5×10 20 / cm 3 Furthermore, the doping concentration of the first gallium nitride layer 160 is 5 × 10⁻⁶. 18 / cm3 ~10 20 / cm 3 Specifically, the doping concentration of the first gallium nitride layer 160 can be, but is not limited to, 5 × 10⁻⁶. 18 / cm 3 6×10 18 / cm 3 7×10 18 / cm 3 8×10 18 / cm 3 9×10 18 / cm 3 10 19 / cm 3 2×10 19 / cm 3 3×10 19 / cm 3 4×10 19 / cm 3 5×10 19 / cm 3 6×10 19 / cm 3 7×10 19 / cm 3 8×10 19 / cm 3 9×10 19 / cm 3 Or 10 20 / cm 3 Understandably, the doping element in the first gallium nitride layer 160 may be, but is not limited to, magnesium.

[0082] Furthermore, the present invention also provides a method for fabricating the light-emitting diode 10 as described above, wherein a buffer layer 110, an unintentionally doped layer 120, a gallium nitride composite layer 130, a multi-quantum-well light-emitting layer 140, an electron blocking layer 150 and a first gallium nitride layer 160 are sequentially formed on a silicon substrate 100.

[0083] Understandably, the method for forming each layer of the aforementioned light-emitting diode 10 may be, but is not limited to, chemical vapor deposition.

[0084] In one specific example, the conditions for forming the buffer layer 110 include a growth temperature of 750°C to 1100°C. Preferably, the growth temperature of the buffer layer 110 is 800°C to 1050°C.

[0085] In one specific example, the conditions for forming the unintentionally doped layer 120 include a growth temperature of 950°C to 1300°C. Preferably, the growth temperature of the unintentionally doped layer 120 is 1050°C to 1200°C.

[0086] In a specific example, the conditions for forming the gallium nitride composite layer 130 include: a growth temperature of 800℃ to 1200℃ and a growth pressure of 30 torr to 250 torr.

[0087] Furthermore, the growth temperature of the second gallium nitride layer 131 is 1100℃~1100℃, and the growth pressure is 80 torr~120 torr.

[0088] Furthermore, the growth temperature of the third gallium nitride layer 133 is 1000℃~1100℃, and the growth pressure is 80 torr~120 torr.

[0089] In a preferred example, the growth temperature of the fourth gallium nitride layer 134 is 900℃~1000℃, and the growth pressure is 180 torr~220 torr.

[0090] The growth temperature of the aluminum gallium nitride (AlGaN) layer in the gallium nitride composite layer 130 is 900℃~1000℃, and the growth pressure is 30 torr~70 torr.

[0091] In a specific example, the conditions for forming the multi-quantum-well light-emitting layer 140 include a growth temperature of 600℃ to 1100℃.

[0092] In a specific example, the conditions for forming the electron blocking layer 150 include a growth temperature of 800℃ to 1200℃.

[0093] In a specific example, the conditions for forming the first gallium nitride layer 160 include a growth temperature of 800°C to 1200°C.

[0094] In the above-mentioned structure of light-emitting diode 10, GaN crystal is epitaxially grown. By setting a gallium nitride composite layer 130, which includes a third gallium nitride layer 133 with a first doping concentration, an aluminum gallium nitride layer 132, a fourth gallium nitride layer 134 with a second doping concentration, and a fourth gallium nitride layer 134 with a third doping concentration, and defining the doping gradient in the gallium nitride layer, the crystal quality and electron migration of gallium nitride in the gallium nitride composite layer 130 can be effectively improved, and leakage channels can be reduced, thereby improving the antistatic capability and reverse leakage capability of light-emitting diode 10.

[0095] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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, they should be considered to be within the scope of this specification.

[0096] The embodiments described above are merely illustrative of several implementations of the present invention, designed to facilitate a detailed understanding of the technical solutions of the present invention, but should not be construed as limiting the scope of protection of the invention patent. 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 scope of protection of the present invention. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided by the present invention through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this invention patent should be determined by the content of the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. A light-emitting diode, characterized in that, It includes a silicon substrate, a buffer layer, an unintentionally doped layer, a gallium nitride composite layer, a multi-quantum-well light-emitting layer, an electron blocking layer, and a first gallium nitride layer, which are stacked in sequence. The gallium nitride composite layer comprises, in sequence, a second gallium nitride layer with a first doping concentration, an aluminum gallium nitride layer, a third gallium nitride layer with a second doping concentration, and a fourth gallium nitride layer with a third doping concentration, wherein the first doping concentration is higher than the third doping concentration, and the third doping concentration is higher than the second doping concentration. The second gallium nitride layer, the third gallium nitride layer, and the fourth gallium nitride layer have a first conductivity type, and the electron blocking layer and the first gallium nitride layer have a second conductivity type, wherein the first conductivity type is opposite to the second conductivity type.

2. The light-emitting diode as described in claim 1, characterized in that, The gallium nitride composite layer satisfies one or more of the following conditions: (1) The first doping concentration is 8×10 19 / cm 3 ~4×10 19 / cm 3 ; (2) The second doping concentration is 8×10 16 / cm 3 ~2×10 18 / cm 3 ; (3) The third doping concentration is 8×10 17 / cm 3 ~2×10 19 / cm 3 ; (4) The thickness of the second gallium nitride layer is 0.5 μm to 2.5 μm; (5) The thickness of the aluminum gallium nitride layer is 40nm to 120nm; (6) The thickness of the third gallium nitride layer is 80nm to 520nm; (7) The thickness of the fourth gallium nitride layer is 5nm to 120nm.

3. The light-emitting diode as described in claim 1, characterized in that, The buffer layer satisfies one or more of the following conditions: (1) The material of the buffer layer is selected from at least one of gallium nitride, aluminum gallium nitride, indium aluminum gallium nitride, and indium gallium nitride; (2) The thickness of the buffer layer is 200nm to 1100nm.

4. The light-emitting diode as described in claim 1, characterized in that, The unintentionally doped layer satisfies one or more of the following conditions: (1) The material of the unintentionally doped layer is gallium nitride; (2) The thickness of the unintentionally doped layer is 0.2 μm to 1.2 μm.

5. The light-emitting diode as described in claim 1, characterized in that, The multi-quantum-well light-emitting layer includes n stacked base layers, each base layer including stacked barrier layers and potential well layers, the barrier layers being in contact with the gallium nitride composite layer, where n is an integer from 3 to 12.

6. The light-emitting diode as described in claim 5, characterized in that, The multi-quantum-well light-emitting layer satisfies one or more of the following conditions: (1) The material of the barrier layer is Al x Ga 1-x N, where x is 0 to 0.5; (2) The material of the potential well layer is In y Ga 1-y N, where y is 0 to 0.4; (3) The thickness of the barrier layer is 2nm to 12nm; (4) The thickness of the potential well layer is 1 nm to 6 nm.

7. The light-emitting diode as described in claim 1, characterized in that, The electron blocking layer satisfies one or more of the following conditions: (1) The material of the electron blocking layer is selected from one or more of gallium nitride, aluminum gallium nitride, indium aluminum gallium nitride, and aluminum nitride; (2) The thickness of the electron blocking layer is 20nm to 90nm; (3) The doping concentration of the electron blocking layer is 10 18 / cm 3 ~5×10 19 / cm 3 .

8. The light-emitting diode as described in claim 1, characterized in that, The first gallium nitride layer satisfies one or more of the following conditions: (1) The thickness of the first gallium nitride layer is 20nm to 170nm; (2) The doping concentration of the first gallium nitride layer is 10 18 / cm 3 ~5×10 20 / cm 3 .

9. A method for fabricating a light-emitting diode as described in any one of claims 1 to 8, characterized in that, The buffer layer, the unintentionally doped layer, the gallium nitride composite layer, the multi-quantum well light-emitting layer, the electron blocking layer, and the first gallium nitride layer are sequentially formed on the silicon substrate.

10. The method for fabricating a light-emitting diode as described in claim 9, characterized in that, One or more of the following conditions must be met: (1) The conditions for the formation of the buffer layer include: a growth temperature of 750℃~1100℃; (2) The conditions for the formation of the unintentionally doped layer include: a growth temperature of 950℃~1300℃; (3) The conditions for forming the gallium nitride composite layer include: a growth temperature of 800℃~1200℃ and a growth pressure of 30 torr~250 torr; (4) The conditions for forming the multi-quantum well light-emitting layer include: a growth temperature of 600℃~1100℃; (5) The conditions for the formation of the electron blocking layer include: a growth temperature of 800℃~1200℃; (6) The conditions for forming the first gallium nitride layer include: a growth temperature of 800℃~1200℃.

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