阅读说明：本技术 紫外半导体发光元件 (Ultraviolet semiconductor light emitting element ) 是由 郑锦坚 高默然 毕京锋 范伟宏 曾家明 张成军 于 2021-06-15 设计创作，主要内容包括：本发明提供了一种紫外半导体发光元件,从下至上依次包括：衬底、n型半导体层、老化漏电控制层、量子阱层以及p型半导体层,其中所述老化漏电控制层为第一结构层与第二结构层组成的超晶格结构。本发明通过在n型半导体层和量子阱层之间增加具有超晶格结构的老化漏电控制层,能够改善紫外半导体发光元件的老化漏电性能。(The invention provides an ultraviolet semiconductor light-emitting element, which sequentially comprises the following components from bottom to top: the semiconductor device comprises a substrate, an n-type semiconductor layer, an aging leakage control layer, a quantum well layer and a p-type semiconductor layer, wherein the aging leakage control layer is a superlattice structure consisting of a first structural layer and a second structural layer. According to the invention, the aging leakage control layer with the superlattice structure is added between the n-type semiconductor layer and the quantum well layer, so that the aging leakage performance of the ultraviolet semiconductor light-emitting element can be improved.)

1. An ultraviolet semiconductor light-emitting element is characterized by comprising the following components in sequence from bottom to top: the semiconductor device comprises a substrate, an n-type semiconductor layer, an aging leakage control layer, a quantum well layer and a p-type semiconductor layer, wherein the aging leakage control layer is a superlattice structure consisting of a first structural layer and a second structural layer.

2. The ultraviolet semiconductor light-emitting element according to claim 1, wherein the material of the second structure layer comprises AlN.

3. The ultraviolet semiconductor light-emitting element as claimed In claim 1, wherein the material of the first structure layer comprises GaN and In_zGa_1-zN, wherein z is in the range of 0 to 0.2.

4. The ultraviolet semiconductor light-emitting element according to claim 3, wherein a material of the first structure layer comprises In_zGa_1-zAnd N, the In component content of the first structural layer is lower than that of the quantum well layer.

5. The ultraviolet semiconductor light-emitting element as claimed In claim 4, wherein the In component content of the quantum well layer is 0 to 0.3.

6. The ultraviolet semiconductor light-emitting element as claimed in claim 1, wherein the thickness of the first structural layer is at least 2 times the thickness of the second structural layer.

7. The ultraviolet semiconductor light-emitting element according to claim 1, wherein the thickness of the first structure layer is 3nm to 8 nm.

8. The ultraviolet semiconductor light-emitting element as claimed in claim 1, wherein the thickness of the second structure layer is 0.5nm to 3 nm.

9. The ultraviolet semiconductor light-emitting element according to claim 1, wherein the aging leakage control layer has an extremely small Si doping concentration, and the Si doping concentration of the aging leakage control layer is less than 1E17cm^-3。

10. The ultraviolet semiconductor light-emitting element according to claim 1, wherein the period of the superlattice structure of the aging leakage control layer is m, and 5. ltoreq. m.ltoreq.40.

11. The ultraviolet semiconductor light-emitting element according to claim 1, wherein the p-type semiconductor layer comprises a p-type electron blocking layer and a p-type contact layer on the p-type electron blocking layer.

12. The ultraviolet semiconductor light-emitting element as claimed in claim 11, wherein the material of the p-type electron blocking layer comprises Al_yGa_1-yN, wherein y ranges from 0.2 to 1; the p-type contact layer is made of GaN and Al_kGa_1-kN, wherein k is in the range of 0-0.45.

13. The ultraviolet semiconductor light-emitting element according to claim 1, wherein a material of the n-type semiconductor layer comprises Al_xGa_1-xN, and x ranges from 0 to 0.6.

Technical Field

The invention relates to the technical field of semiconductors, in particular to an ultraviolet semiconductor light-emitting element.

Background

The ultraviolet semiconductor light-emitting element has the wavelength range of 200-300 nm, and the emitted ultraviolet light can break DNA or RNA of viruses and bacteria, directly kill the viruses and the bacteria, and can be widely applied to the sterilization and disinfection fields of air purification, tap water sterilization, household air conditioner sterilization, automobile air conditioner sterilization and the like.

The existing ultraviolet semiconductor light-emitting element uses a quantum well layer with low In component, and because the In component is too low, the quantum well layer can not form In component fluctuation and a V-pits structure similar to those In a blue light semiconductor light-emitting element to perform quantum restriction on carriers, so that the carriers can not be effectively restricted outside a leakage channel, electrons can jump into the leakage channel In the aging process, and the leakage current after aging is larger than 2 muA. The existing ultraviolet semiconductor light-emitting element uses a superlattice structure composed of InGaN and GaN, or a superlattice structure composed of InGaN and AlGaN, or a superlattice structure composed of GaN and AlGaN as an insertion layer between a quantum well layer and an n-type semiconductor layer, and the structure can perform the functions of stress release and current expansion, but can not effectively control and improve the aging leakage phenomenon, so that the leakage current after the aging leakage for 1000 hours is generally more than 5 muA, and the aging leakage failure is caused.

Disclosure of Invention

The invention aims to provide an ultraviolet semiconductor light-emitting element to improve the aging leakage performance of the ultraviolet semiconductor light-emitting element.

In order to achieve the above and other related objects, the present invention provides an ultraviolet semiconductor light emitting device, which comprises, from bottom to top: the semiconductor device comprises a substrate, an n-type semiconductor layer, an aging leakage control layer, a quantum well layer and a p-type semiconductor layer, wherein the aging leakage control layer is a superlattice structure consisting of a first structural layer and a second structural layer.

Optionally, in the ultraviolet semiconductor light emitting element, a material of the second structure layer includes AlN.

Optionally, In the ultraviolet semiconductor light emitting element, a material of the first structure layer includes GaN and In_zGa_1-zN, wherein z is in the range of 0 to 0.2.

Optionally, In the ultraviolet semiconductor light emitting element, a material of the first structure layer includes In_zGa_1-zAnd N, the In component content of the first structural layer is lower than that of the quantum well layer.

Optionally, In the ultraviolet semiconductor light emitting element, the In component content of the quantum well layer is 0-0.3.

Optionally, in the ultraviolet semiconductor light emitting element, a thickness of the first structural layer is at least 2 times a thickness of the second structural layer.

Optionally, in the ultraviolet semiconductor light emitting element, the thickness of the first structure layer is 3nm to 8 nm.

Optionally, in the ultraviolet semiconductor light emitting element, the thickness of the second structure layer is 0.5nm to 3 nm.

Optionally, in the ultraviolet semiconductor light emitting element, the aging leakage control layer has an extremely small Si doping concentration, and the Si doping concentration of the aging leakage control layer is less than 1E17cm^-3。

Optionally, in the ultraviolet semiconductor light emitting element, the period of the superlattice structure of the aging leakage control layer is m, and m is greater than or equal to 5 and less than or equal to 40.

Optionally, in the ultraviolet semiconductor light emitting element, the p-type semiconductor layer includes a p-type electron blocking layer and a p-type contact layer on the p-type electron blocking layer.

Optionally, in the ultraviolet semiconductor light emitting element, a material of the p-type electron blocking layer includes Al_yGa_1-yN, wherein y ranges from 0.2 to 1; the p-type contact layer is made of GaN and Al_kGa_1-kN, wherein k is in the range of 0-0.45.

Optionally, in the ultraviolet semiconductor light emitting element, the n-type semiconductorThe material of the layer comprises Al_xGa_{1- x}N, and x ranges from 0 to 0.6.

Compared with the prior art, the technical scheme of the invention has the following beneficial effects:

according to the invention, the aging leakage control layer with the superlattice structure is added between the n-type semiconductor layer and the quantum well layer, so that dislocation and defects can be blocked, and a leakage channel is reduced; meanwhile, one of the composition materials of the superlattice structure of the aging leakage control layer is AlN, and the high potential barrier of the AlN can play a role in effectively preventing aging leakage. Therefore, the aging leakage control layer can effectively inhibit electrons in the aging process from leaking into a leakage channel, and the leakage current after aging for 1000 hours is controlled to be within 0.2 muA.

Drawings

Fig. 1 is a schematic structural diagram of an ultraviolet semiconductor light emitting device according to an embodiment of the present invention;

in fig. 1:

100-substrate, 101-buffer layer, 102-n type semiconductor layer, 103-aging leakage control layer, 104-quantum well layer, 105-p type electronic barrier layer and 106-p type contact layer.

Detailed Description

The existing ultraviolet semiconductor light-emitting element uses a quantum well layer with low In component, and because the In component is too low, the quantum well layer can not form In component fluctuation and a V-pits structure similar to those In a blue light semiconductor light-emitting element to perform quantum restriction on carriers, so that the carriers can not be effectively restricted outside a leakage channel, and electrons can jump into the leakage channel In the aging process to cause the aging leakage current to be more than 2 muA. The existing ultraviolet semiconductor light-emitting element uses a superlattice structure composed of InGaN and GaN, or a superlattice structure composed of InGaN and AlGaN, or a superlattice structure composed of GaN and AlGaN as an insertion layer between a quantum well and an n-type semiconductor, and the structure can perform the functions of stress release and current expansion, but can not effectively control and improve aging leakage, so that the leakage current after 1000 hours of aging leakage is generally more than 5 muA, and the aging leakage failure is caused.

In order to improve the aging leakage performance of the ultraviolet semiconductor light-emitting element, the invention provides the ultraviolet semiconductor light-emitting element, wherein an aging leakage control layer with a superlattice structure is inserted between an n-type semiconductor layer and a quantum well layer, and electrons in an aging process can be effectively inhibited from leaking into a leakage channel through the aging leakage control layer with low Si doping concentration, so that the leakage current after aging for 1000 hours is controlled within 0.2 muA.

The ultraviolet semiconductor light emitting element according to the present invention will be described in further detail with reference to the accompanying drawings and specific examples. The advantages and features of the present invention will become more apparent from the following description. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

Referring to fig. 1, the ultraviolet semiconductor light emitting device provided in this embodiment sequentially includes, from bottom to top: the semiconductor device comprises a substrate 100, an n-type semiconductor layer 102, a aging leakage control layer 103, a quantum well layer 104 and a p-type semiconductor layer, wherein the aging leakage control layer 103 is a superlattice structure consisting of a first structural layer and a second structural layer.

The substrate 100 may be one of a homogeneous or heterogeneous substrate, and may include GaN, AlN, Ga₂O₃SiC, Si, sapphire, ZnO single crystal substrates, and high temperature resistant metal substrates with pre-deposited AlN films. A substrate capable of transmitting light emitted from the quantum well layer 104 and emitting light from the substrate side, such as a sapphire substrate, is preferably used. In order to improve light extraction efficiency, the surface of the light exit side of the substrate 100 or the opposite side thereof may be in a concave-convex shape.

A Buffer layer (Buffer)101 may be formed on the substrate 100. The buffer layer 101 is used to reduce lattice mismatch between the substrate 100 and the epitaxial layer, so as to reduce the possibility of defects and dislocations in the grown epitaxial layer, and improve the crystal quality. The buffer layer 101 is not limited to one material, and may be a plurality of materials, combinations of different dopants and different doping contents, etc., and all the buffer layer materials disclosed so far are within the scope of the present invention. Preferably, the buffer layer 101 is made of nitride, for example, the buffer layer 101 is made of AlN.

The n-type semiconductor layer 102 may be disposed on the substrate 100 via the buffer layer 101, or the n-type semiconductor layer 102 may be disposed directly on the substrate 100. The n-type semiconductor layer 102 may be a conventional n-type layer, such as Al_xGa_1-xN, wherein x is in the range of 0-0.6. The n-type semiconductor layer 102 functions as an n-type layer by doping an n-type dopant, and specific examples of the n-type dopant include, but are not limited to, silicon (Si), germanium (Ge), tin (Sn), sulfur (S), oxygen (O), titanium (Ti), zirconium (Zr), and the like. The dopant concentration of the n-type dopant may be a dopant concentration at which the n-type semiconductor layer 102 can function as an n-type layer. Further, the n-type dopant in the n-type semiconductor layer 102 is preferably Si, and the doping concentration of Si is preferably 5E18cm^-3～5E19cm^-3. The thickness of the n-type semiconductor layer 102 is preferably 1 μm to 3.5 μm. The n-type semiconductor layer 102 preferably has a band gap wider than that of the quantum well layer 104 (a well layer in the case of a multiple quantum well structure) and has transparency to ultraviolet light to be emitted. The n-type semiconductor layer 102 may have a single-layer structure or a multi-layer structure, or may have a superlattice structure.

The aging leakage control layer 103 is a superlattice structure composed of a first structural layer and a second structural layer, and the period of the superlattice structure of the aging leakage control layer 103 is m, and m is greater than or equal to 5 and less than or equal to 40. The material of the first structural layer comprises GaN and In_zGa_1-zN, wherein z is in the range of 0 to 0.2. The material of the second structure layer includes AlN, but is not limited thereto. Therefore, the aging leakage control layer 103 may be a superlattice structure composed of GaN and AlN or In_zGa_1-zA superlattice structure consisting of N and AlN. The aging leakage control layer 103 adopts a superlattice structure composed of GaN and AlN or In_zGa_1-zThe superlattice structure composed of N and AlN not only can play a role in stress release and current expansion, but also can prevent dislocation and defect in the epitaxial growth process, especially the threading dislocation is extremely largeThe leakage rate of electrons to the leakage channel can be reduced, namely, the electrons in the aging process can be effectively inhibited from leaking to the leakage channel, and the aging leakage performance of the ultraviolet semiconductor light-emitting element is improved.

The material of the first structural layer comprises In_zGa_1-zN, the In composition content of the first structural layer is lower than that of the quantum well layer 104. The In component content of the quantum well layer 104 is preferably 0 to 0.3. The aging leakage control layer 103 is doped with an n-type dopant, preferably doped with Si. The aging leakage control layer 103 must have very low doped Si to achieve the aging leakage control effect, and also enable the n-type semiconductor layer to achieve the effective current lateral expansion effect. The first structural layer may be doped with Si, and/or the second structural layer may be doped with Si, that is, only the first structural layer may be doped with Si, only the second structural layer may be doped with Si, or both the first structural layer and the second structural layer may be doped with Si. The Si doping concentration of the aging leakage control layer 103 is less than 1E17cm^-3. The Si doping concentration of the aging leakage control layer 103 is not more than 1E17cm^-3Otherwise, it will cause electrons to leak into the leakage path, causing aging leakage failure.

The thickness of the first structural layer is at least 2 times of that of the second structural layer, so that the effect of improving aging leakage is achieved. That is, the aged leakage control layer 103 must satisfy the condition that the GaN thickness is 2 times or more the AlN thickness, or In_zGa_{1- z}The thickness of N is 2 times or more the thickness of AlN. Preferably, the thickness of the first structural layer is 3nm to 8nm, and the thickness of the second structural layer is 0.5nm to 3 nm. The thickness of the second structural layer, namely the thickness of AlN must be more than 0.5nm, otherwise, the function of effectively preventing aging and electric leakage cannot be realized; the thickness of the second structure layer, namely the thickness of AlN, cannot be larger than 3nm, because the AlN barrier is very high, electrons are difficult to tunnel and jump and inject into the quantum well due to the too thick thickness, and the AlN resistance is very large, therefore, the voltage of the ultraviolet semiconductor light-emitting element is abnormally high and the brightness is seriously reduced due to the too thick thickness of the second structure layer.

In the ultraviolet semiconductor light emitting element in this embodiment, the aging leakage control layer 103 doped with Si is capable of effectively suppressing leakage of electrons into a leakage channel during aging, so that leakage current after aging for 1000 hours is controlled to be within 0.2 μ a.

The aged leakage control layer 103 may be applied to semiconductor light emitting elements of all other wavelength ranges, for example, deep ultraviolet semiconductor light emitting elements, violet semiconductor light emitting elements, blue semiconductor light emitting elements, green semiconductor light emitting elements, and yellow semiconductor light emitting elements, with a wavelength range of 200nm to 550 nm.

The quantum well layer 104 is formed on the aging leakage control layer 103. The quantum well layer 104 may be a superlattice structure composed of InGaN and AlGaN, or a superlattice structure composed of GaN and AlGaN, but is not limited thereto. Preferably, the quantum well layer 104 may be a superlattice structure composed of InGaN and AlGaN. The quantum well layer 104 generally includes a well layer and a barrier layer, for example, when the quantum well layer 104 is a superlattice structure composed of InGaN and AlGaN, the well layer is an InGaN layer, and the barrier layer is an AlGaN layer. The In component content of InGaN In the quantum well layer 104 is greater than the In component content of InGaN In the aging leakage control layer 103, and the In component content In the quantum well layer 104 is preferably 0 to 0.3. In the barrier layer of the quantum well layer 104, that is, AlGaN in the quantum well layer 104, an n-type dopant, preferably Si, is doped, and the Si doping concentration is preferably 1E17cm^-3～5E19cm^-3。

A p-type semiconductor layer disposed on the quantum well layer 104, and the p-type semiconductor layer may include a p-type electron blocking layer 105 and a p-type contact layer 106. The p-type electron blocking layer 105 is used for blocking electrons, preventing the electrons from overflowing to the p-type contact layer 106, and further injecting the electrons into the quantum well layer 104, so that the occurrence of non-radiative recombination is reduced, and the light emitting efficiency of the ultraviolet semiconductor light emitting element is further improved.

The material of the p-type electron blocking layer 105 is preferably Al_yGa_1-yN and y are in the range of 0.2 to 1, but not limited thereto. The thickness of the p-type electron blocking layer 105 is not particularly limited. In addition, the first and second substrates are,examples of the p-type dopant doped into the p-type electron blocking layer 105 include, but are not limited to, magnesium (Mg), zinc (Zn), calcium (Ca), beryllium (Be), manganese (Mn), and the like. The p-type dopant is preferably Mg. The dopant concentration of the p-type electron blocking layer 105 is not particularly limited as long as it can function as a p-type semiconductor layer.

The p-type contact layer 106 is disposed on the p-type electron blocking layer 105. The p-type contact layer 106 is a layer for reducing the contact resistance between the p-side electrode disposed directly above it and the p-type electron blocking layer 105. The p-type contact layer 106 is made of GaN and Al_kGa_1-kAt least one of N, but not limited thereto, k is in the range of 0 to 0.45. The p-type contact layer 106 of the ultraviolet light emitting element is generally a p-type GaN layer which is likely to increase the hole concentration, and p-type Al may be used_kGa_1-kN layer although Al_kGa_1-kThe N layer may have a slightly lower hole concentration than the GaN layer, but can transmit p-type Al due to ultraviolet light emitted from the light emitting layer_kGa_1-kThe N layers improve the light extraction efficiency of the entire ultraviolet light emitting element, and can improve the light emission output of the ultraviolet light emitting element.

The ultraviolet semiconductor layer may be formed by a known thin film forming method such as a Metal Organic Chemical Vapor Deposition (MOCVD) method, a Molecular Beam Epitaxy (MBE) method, a Hydride Vapor Phase Epitaxy (HVPE) method, a Plasma Enhanced Chemical Vapor Deposition (PECVD), a sputtering method, and the n-type semiconductor layer, the aging leakage control layer, the quantum well layer, and the p-type semiconductor layer may be formed by a MOCVD method.

In the ultraviolet semiconductor light emitting element provided in this embodiment, the aging leakage control layer having a superlattice structure is added between the n-type semiconductor layer and the quantum well layer, so that dislocation and defects can be blocked, and a leakage channel can be reduced; meanwhile, one of the composition materials of the superlattice structure of the aging leakage control layer is AlN, and the high potential barrier of the AlN can play a role in effectively preventing aging leakage. Therefore, the aging leakage control layer can effectively inhibit electrons in the aging process from leaking into a leakage channel, and the leakage current after aging for 1000 hours is controlled to be within 0.2 muA.

In addition, it is to be understood that while the present invention has been described in conjunction with the preferred embodiments thereof, it is not intended to limit the invention to those embodiments. It will be apparent to those skilled in the art from this disclosure that many changes and modifications can be made, or equivalents modified, in the embodiments of the invention without departing from the scope of the invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the scope of the protection of the technical solution of the present invention, unless the contents of the technical solution of the present invention are departed.

It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. It must be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a step" means a reference to one or more steps and may include sub-steps. All conjunctions used should be understood in the broadest sense. Thus, the word "or" should be understood to have the definition of a logical "or" rather than the definition of a logical "exclusive or" unless the context clearly dictates otherwise. Structures described herein are to be understood as also referring to functional equivalents of such structures. Language that can be construed as approximate should be understood as such unless the context clearly dictates otherwise.