A deep ultraviolet light emitting diode having a patterned photonic absorption structure and a method of fabricating the same
By inserting oxide nanostructures into deep ultraviolet LEDs, the problems of low hole injection efficiency and poor light extraction efficiency are solved, thereby achieving higher luminous efficiency and photoelectric conversion efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HEBEI UNIV OF TECH
- Filing Date
- 2024-12-30
- Publication Date
- 2026-07-10
Smart Images
Figure CN119698140B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of light-emitting diode semiconductor technology, specifically to a deep ultraviolet light-emitting diode with a patterned photon absorption structure and its fabrication method. Background Technology
[0002] With the continuous development of semiconductor device fabrication technology, the research of ultraviolet (UV) light-emitting diodes (LEDs) has become an important topic. By alloying gallium nitride (GaN) with aluminum nitride (ANH), the emission wavelength of GaN-based LEDs can be tuned to almost cover the entire ultraviolet (UV) spectrum (200-400 nm), with LEDs emitting wavelengths between 200 nm and 280 nm being called deep ultraviolet (DUV) LEDs. Depending on their emission wavelength, UV LED devices have broad application prospects in water purification, UV curing, optical communication, and phototherapy. Therefore, developing DUV LEDs with high external quantum efficiency (EQE), high optical power, and high electro-optical conversion efficiency (WPE) is a goal. However, at present, deep ultraviolet LEDs still suffer from relatively low EQE and poor WPE, limiting their further commercial applications. Deep ultraviolet LEDs often use magnesium (Mg) as a p-type dopant, but the high activation energy and low hole mobility of Mg limit hole injection efficiency. Furthermore, due to the very high proportion of TM polarized light in deep ultraviolet (DUV) LEDs, and the presence of numerous absorbing materials such as metals and pGaN, the light from DUV LEDs is difficult to extract and is instead converted into heat, thus reducing the light extraction efficiency. Therefore, improving the hole injection rate in the multi-quantum well of LEDs and preventing the absorption and conversion of deep ultraviolet light into heat is crucial.
[0003] In the current technology, the patent "A Flip-Chip Deep Ultraviolet Light Emitting Diode Chip and Its Fabrication Method" (Publication No.: CN113410356A) mentions a roughening treatment of the P-AlGaN layer. The steps involve etching the P-AlGaN layer with a sodium hydroxide solution of a specific concentration, followed by dry etching of the surface of the etched P-AlGaN layer. By changing the geometry of the interface between the P-AlGaN layer and the p-electrode, the critical angle for total internal reflection is increased, thereby improving the metallic reflectivity of the p-electrode and achieving an improved light extraction efficiency.
[0004] While the above solution effectively improves light extraction efficiency, coarsening the P-AlGaN layer sacrifices the area of the ohmic contacts. This not only affects the current injection efficiency of deep ultraviolet LEDs but may also increase power consumption and reduce the luminous efficiency of deep ultraviolet LEDs. Summary of the Invention
[0005] The purpose of this invention is to address the shortcomings of current technologies by providing a deep ultraviolet (DUV) light-emitting diode (LED) with a patterned photon absorption structure and its fabrication method. The patterned photon absorption structure of this diode is achieved by fabricating an n-type oxide nanostructure on the surface of the P-GaN layer of a conventional flip-chip DUV LED using nanolithography and lift-off techniques. This nanostructure can be a nanopillar structure. Then, a p-electrode is deposited on the oxide nanostructure. The p-electrode can inject holes from the center of the oxide nanostructure, enabling the DUV LED to emit light. This invention improves the hole injection efficiency of the DUV LED and suppresses the conversion of absorbed light into heat energy.
[0006] The technical solution adopted by this invention to solve this technical problem is as follows:
[0007] A deep ultraviolet light-emitting diode with a patterned photon absorption structure.
[0008] The diode comprises, from bottom to top, a substrate, an AlN buffer layer, and an N-type AlGaN layer; wherein, one side of the N-type AlGaN layer is partially exposed, with the exposed area being 5% to 90% of the total surface area of the N-type AlGaN layer; the height of the exposed portion is 5% to 90% of the total height of the N-type AlGaN layer;
[0009] The upper surface of the unexposed N-type AlGaN layer is covered from bottom to top with a multi-quantum well layer, a P-type electron blocking layer, a P-type AlGaN layer, and a P-type GaN layer; the upper surface of the P-type GaN layer is arrayed with oxide nanostructures; the P-type ohmic contact layer is covered on the oxide nanostructures and the P-type GaN layer, also forming an arrayed structure.
[0010] The metal mirror electrode is covered on a P-type ohmic contact layer;
[0011] N-type ohmic electrodes are also distributed on the surface of the exposed portion of the N-type AlGaN layer;
[0012] The oxide nanostructure is made of n-type ZnO or n-type Ga2O3, with a doping concentration of 1*10e15-1*10e20 / cm³. 3 The thickness is between 5 and 500 nm;
[0013] The oxide nanostructure is a nanopillar array with a diameter of 10 nm to 10,000 nm and a spacing of 10 nm to 10,000 nm between the nanopillars; the fill factor is 20% to 80%.
[0014] The substrate is a C-plane sapphire substrate;
[0015] The buffer layer material is AlN, and the thickness is 1~3μm;
[0016] The N-type AlGaN layer material is Al 0.6 Ga 0.4 N, with a thickness of 1~3μm;
[0017] The structure of the multiple quantum well layer is a 5-period Al 0.45 Ga 0.55 N / Al 0.56 Ga 0.44 N layers, where the quantum barrier Al 0.56 Ga 0.44 The thickness of N is set to 11~12 nm, and the quantum well Al 0.45 Ga 0.55 The thickness of N is set to 3~4nm;
[0018] The P-type electron blocking layer material is Al 0.6 Ga 0.4 N, with a thickness of 10~50nm;
[0019] The p-type AlGaN layer material is Al 0.4 Ga 0.6 N, with a thickness of 50~200nm;
[0020] The thickness of the p-type GaN layer is 10~50nm;
[0021] The material of the P-type ohmic contact layer is Ni / Au or Ni / Al;
[0022] The material of the metal reflector electrode is Al;
[0023] The N-type ohmic electrode is made of Cr / Au or Ti / Al / Ti / Au, wherein the projected area of the N-type ohmic electrode is 10-80% of the area of the exposed N-type AlGaN layer;
[0024] The method for fabricating a deep ultraviolet light-emitting diode with a patterned photon absorption structure includes the following steps:
[0025] The first step is to bake the substrate at 1250–1350°C in an MOCVD (metal-organic chemical vapor deposition) or MBE (molecular beam epitaxy) furnace to remove foreign matter from the substrate surface. Then, an AlN buffer layer, an N-type AlGaN layer, a multiple quantum well layer, a P-type electron blocking layer, a P-type AlGaN layer, and a P-type GaN layer are sequentially grown on the sapphire substrate.
[0026] The second step is to spin-coat a positive photoresist layer onto the P-type GaN layer obtained in the first step.
[0027] The third step is to attach a single layer of nanosphere lens layer onto the photoresist layer obtained in the second step.
[0028] The fourth step involves fabricating a photoresist nanostructure on the nanosphere lens layer obtained in the third step using exposure and development processes.
[0029] The fifth step involves growing an oxide structure on the photoresist nanostructure obtained in the fourth step using magnetron sputtering.
[0030] The sixth step involves removing the photoresist mask and the oxides on it using a stripping technique to obtain the oxide nanostructure.
[0031] The seventh step involves fabricating a mesa using photolithography and dry etching processes. This process involves etching oxide nanostructures, P-type GaN layers, P-type AlGaN layers, P-type electron blocking layers, multiple quantum well layers, and N-type AlGaN layers to form a DUV LED epitaxial layer structure that passes through the quantum well structure, and exposing 5-90% of the N-type AlGaN layer.
[0032] The eighth step involves fabricating a mask for the P-type ohmic contact layer using photolithography, exposing 30-100% of the area in the middle of the P-GaN mesa surface. The P-type ohmic contact layer is then deposited using electron beam evaporation or magnetron sputtering. Afterward, the mask and the P-type ohmic contact layer on the mask are stripped off.
[0033] The ninth step involves depositing and photolithographically fabricating an N-type ohmic electrode on the exposed N-type AlGaN layer, with an area of 10–80% of the exposed N-type AlGaN layer area.
[0034] Step 10: Deposit the metal mirror electrode onto the exposed P-type ohmic contact layer.
[0035] The essential features of this invention are:
[0036] Current deep ultraviolet (DUV) LEDs suffer from low luminous efficiency, limiting their further commercial applications. This is partly due to the low doping efficiency of Mg dopant in the p-type region and the low hole mobility, which restricts hole injection efficiency. The imbalance of electron and hole concentrations in multiple quantum wells leads to low radiative recombination efficiency. Furthermore, the very high proportion of TM polar light in DUV LEDs, coupled with the presence of numerous absorbing materials, makes it difficult to extract the light, resulting in its conversion into heat and further reducing luminous efficiency.
[0037] In this invention, an oxide nanostructure is inserted between the p-type GaN layer and the p-type ohmic contact layer. This oxide structure can absorb deep-ultraviolet photons that are difficult to escape from the deep-ultraviolet LED, re-transforming and exciting electron-hole pairs. Under the influence of an electric field, these pairs are re-injected into the quantum well for electron-hole recombination and luminescence, thereby significantly increasing the hole injection rate of the deep-ultraviolet LED, promoting photon cycling, suppressing the conversion of absorbed light into heat, and improving the overall luminous efficiency of the deep-ultraviolet LED.
[0038] The beneficial effects of this invention are:
[0039] (1) The deep ultraviolet light-emitting diode of the present invention is characterized by improving the hole injection efficiency of the deep ultraviolet LED through photon recycling and suppressing the conversion of absorbed light into heat energy. An oxide nanostructure is inserted between the P-type GaN layer and the P-type ohmic contact layer. By absorbing deep ultraviolet photons that are difficult to escape from the deep ultraviolet LED, electron-hole pairs are excited. Holes move under the action of an electric field, thereby doubling the hole injection rate in the quantum well and achieving a more balanced carrier concentration. This enhances the radiative recombination of the deep ultraviolet LED, promotes photon recycling, reduces heat generation, and thus improves the luminous efficiency of the deep ultraviolet LED.
[0040] (2) The deep ultraviolet light-emitting diode with patterned photon absorption structure and its preparation method of the present invention are based on deep ultraviolet LEDs, and oxide nanostructures are made by photolithography and lift-off technology. The process is simple and reliable and the production cost is low. Attached Figure Description
[0041] The invention will now be further described with reference to the accompanying drawings.
[0042] Figure 1 This is a schematic diagram of the epitaxial structure of a flip-chip deep ultraviolet light-emitting diode (LED) chip that currently only has a metal reflector electrode structure.
[0043] Figure 2 This is a schematic diagram of the epitaxial structure of a deep ultraviolet light-emitting diode with a patterned photon absorption structure in the method of the present invention.
[0044] Figure 3 This is a schematic diagram of an epitaxial wafer structure in which a layer of positive photoresist is spin-coated onto a P-type GaN layer, as described in the method of the present invention.
[0045] Figure 4 In the method of the present invention, Figure 3 The diagram shows an epitaxial wafer structure of a nanolens fabricated using nanolithography.
[0046] Figure 5 In the method of the present invention, Figure 4The diagram shows an epitaxial wafer structure made by photoresist nanostructures through exposure and development processes.
[0047] Figure 6 In the method of the present invention, Figure 5 The diagram shows an epitaxial wafer structure of an oxide structure grown in a photoresist nanostructure using magnetron sputtering.
[0048] Figure 7 In the method of the present invention, Figure 6 The diagram shows an epitaxial wafer structure formed by peeling off the photoresist mask and oxides on the mask using a stripping technique.
[0049] Figure 8 In the method of the present invention, Figure 7 The diagram shows an epitaxial wafer structure in which steps are created using photolithography and dry etching processes to expose an N-type AlGaN layer.
[0050] Figure 9 In the method of the present invention, Figure 8 The diagram shows the oxide nanostructure of the product and the epitaxial wafer structure on which the P-type ohmic contact layer and the N-type ohmic electrode are fabricated on the exposed N-type AlGaN layer, respectively.
[0051] Figure 10 In the method of the present invention, Figure 9 A schematic diagram of the structure of the metal reflector electrode fabricated on the P-type ohmic contact layer of the product shown.
[0052] Among them, 101. Substrate, 102. AlN buffer layer, 103. N-type AlGaN layer, 104. Multiple quantum well layer, 105. P-type electron blocking layer, 106. P-type AlGaN layer, 107. P-type GaN layer, 108. Oxide nanostructure, 109. P-type ohmic contact layer, 110. Metal mirror electrode, 111. N-type ohmic electrode, 112. Photoresist layer, 113. Nanolens layer, 114. Photoresist nanostructure, 115. Oxide layer. Detailed Implementation
[0053] The present invention will be further described below with reference to embodiments and accompanying drawings, but this should not be construed as limiting the scope of protection of the claims of this application.
[0054] Figure 1The illustrated embodiment shows that the existing deep ultraviolet LED chip structure with a metal mirror electrode structure sequentially includes: a substrate 101, an AlN buffer layer 102, an N-type AlGaN layer 103, a multiple quantum well layer 104, a P-type electron blocking layer 105, a P-type AlGaN layer 106, a P-type GaN layer 107, a P-type ohmic contact layer 109, a metal mirror electrode 110, and an N-type ohmic electrode 111. For this deep ultraviolet LED structure, only a small portion of photons can escape from the sapphire substrate or be reflected and reused by the metal mirror; most photons are not effectively utilized.
[0055] Example 1
[0056] The deep ultraviolet light-emitting diode chip structure with patterned photon absorption structure in this embodiment is as follows: Figure 2 As shown, from bottom to top, it includes: a substrate 101, an AlN buffer layer 102, and an N-type AlGaN layer 103; wherein, the right side portion of the N-type AlGaN layer 103 is exposed, and the exposed area is 5% of the total surface area of the N-type AlGaN layer 103; the height of the exposed portion is 5% of the total height of the N-type AlGaN layer 103.
[0057] The upper surface of the unexposed N-type AlGaN layer 103 is sequentially covered from bottom to top with a multi-quantum well layer 104, a P-type electron blocking layer 105, a P-type AlGaN layer 106, and a P-type GaN layer 107; an oxide nanostructure 108 is arrayed on the upper surface of the P-type GaN layer 107; a P-type ohmic contact layer 109 covers the oxide nanostructure 108 and the P-type GaN layer 107, and also forms an arrayed structure.
[0058] Metal mirror electrode 110 covers P-type ohmic contact layer 109;
[0059] The surface of the exposed portion of the N-type AlGaN layer 103 is further provided with N-type ohmic electrodes 111; the area of the N-type ohmic electrodes 111 is 80% of the area of the exposed portion of the N-type AlGaN layer 103.
[0060] The substrate 101 described above is made of sapphire, and the epitaxial growth of the structure is along the
[0001] direction. The substrate is square in shape with a side length of [missing information].
[0061] 380μm; buffer layer 102 is made of AlN with a thickness of 2μm; N-type AlGaN layer 103 is made of Al 0.6 Ga 0.4 N, with a thickness of 1 μm; the structure of the multi-quantum well layer 104 is a 5-period Al. 0.45 Ga 0.55 N / Al 0.56Ga 0.44 N layers, where the quantum barrier Al 0.56 Ga 0.44 The thickness of N is set to 12 nm, and the quantum well Al 0.45 Ga 0.55 The thickness of N is set to 3 nm; the P-type electron blocking layer 105 material is Al. 0.6 Ga 0.4 N, with a thickness of 20 nm; the p-type AlGaN layer 106 material is Al 0.4 Ga 0.6 The N-type GaN layer is 125 nm thick; the p-type GaN layer 107 is 50 nm thick; the oxide nanostructure 108 material is cylindrical n-type ZnO with a doping concentration of 1*10e15 / cm³. 3 The diameter is 10000 nm, the spacing is 10000 nm, the fill rate is 20%, and the height is 500 nm. The p-type ohmic contact layer 109 is made of Ni / Au and is uniformly distributed on the surface of the p-type GaN layer 107 and the oxide nanostructure 108. Its minimum thickness in the horizontal direction and the minimum thickness in the vertical direction are both 20 nm. The metal mirror electrode 110 is made of metallic Al and fills the spacing between the p-type ohmic contact layers 109. Its thickness above the p-type ohmic contact layer 109 is 200 nm. The N-type ohmic electrode 111 is made of Ti / Al / Ti / Au, with a thickness of 200 nm and an area of 80% of the exposed portion of the N-type AlGaN layer 103.
[0062] The fabrication method of the above-mentioned deep ultraviolet light-emitting diode chip structure with patterned photon absorption structure is as follows:
[0063] The first step involves baking the substrate at 1250–1350 °C in an MOCVD (Metal-Organic Chemical Vapor Deposition) or MBE (Molecular Beam Epitaxy) furnace to remove foreign matter from the substrate surface. Then, an AlN buffer layer 102 with a thickness of 2 μm is sequentially grown on the sapphire substrate at 1250 °C; an N-type AlGaN layer 103 with a thickness of 1 μm; and a multi-quantum well layer 104 consisting of five AlGaN cycles. 0.45 Ga 0.55 N / Al 0.56 Ga 0.44 N layers, where the quantum barrier Al 0.56 Ga 0.44 The thickness of N is 12 nm, and the quantum well Al 0.45 Ga 0.55 The thickness of N is 3nm; the thickness of the P-type electron blocking layer 105 is 20nm; the thickness of the P-type AlGaN layer 106 is 125nm; the thickness of the P-type GaN layer 107 is 50nm.
[0064] The second step involves spin-coating a positive photoresist layer 112 with a thickness of 500 nm onto the P-type GaN layer 107 obtained in the first step. For example... Figure 3 As shown;
[0065] The third step involves attaching a single-layer SiO2 nanolens layer 113 with a diameter of 20,000 nm onto the photoresist layer 112 obtained in the second step. (Example:) Figure 4 As shown;
[0066] The fourth step involves an exposure process on the nanolens layer 113 obtained in the third step. Through the light-gathering effect of the SiO2 nanospheres, a difference in solubility is created between the portion of the nanospheres in contact with the photoresist and the rest of the photoresist. A development process then dissolves the portion of the nanospheres in contact with the photoresist, fabricating the photoresist nanostructure 114. In the photoresist nanostructure 114, the nanopore diameter is 10000 nm. (The text abruptly ends here.) Figure 5 As shown;
[0067] Fifth, an oxide structure 115 is grown on the photoresist nanostructure 114 obtained in step four using magnetron sputtering. For example... Figure 6 As shown;
[0068] Step six involves using a stripping technique to remove the photoresist mask and the oxide on it, yielding the oxide nanostructure 108 with a diameter of 10000 nm and a thickness of 500 nm. (Example:) Figure 7 As shown;
[0069] Step 7 involves creating steps using photolithography and dry etching to etch the oxide nanostructure 108, P-type GaN layer 107, P-type AlGaN layer 106, P-type electron blocking layer 105, multiple quantum well layer 104, and N-type AlGaN layer 103 into a DUV LED epitaxial layer structure that penetrates the quantum well structure, exposing 5% of the N-type AlGaN layer 103. Figure 8 As shown;
[0070] The eighth step involves fabricating a mask for the P-type ohmic contact layer 109 using photolithography, exposing 100% of the area in the middle of the surface of the P-type GaN layer mesa 107. The P-type ohmic contact layer 109 is deposited by electron beam evaporation or magnetron sputtering. The P-type ohmic contact layer 109 is uniformly distributed on the surface of the P-type GaN layer 107 and the oxide nanostructure 108. Its material is Ni / Au, and its minimum thickness in the horizontal direction and the minimum thickness in the vertical direction are both 20 nm. After that, the mask and the P-type ohmic contact layer 109 on the mask are peeled off.
[0071] The ninth step involves depositing and photolithographically fabricating an N-type ohmic electrode 111 on the exposed N-type AlGaN layer 103. The electrode has a thickness of 200 nm and an area that is 80% of the area of the exposed N-type AlGaN layer. For example... Figure 9 As shown;
[0072] Step 10: Deposit the metal mirror electrode 110 onto the exposed P-type ohmic contact layer 109, filling the gaps between the P-type ohmic contact layers 109. The electrode's thickness above the P-type ohmic contact layer 109 is 200 nm. Figure 10 As shown;
[0073] This results in a deep ultraviolet light-emitting diode chip structure with a patterned photon absorption structure, as described in this embodiment.
[0074] Example 2
[0075] The other steps are the same as in Example 1, except that the oxide nanostructure 108 material is replaced with n-type Ga2O3 instead of n-type ZnO.
[0076] This invention can enhance the hole injection efficiency in the active region, and has a significant effect on deep ultraviolet LEDs with unbalanced carrier injection.
[0077] The above embodiments achieve the following: combining deep ultraviolet LEDs with oxide nanostructures enhances the hole injection capability in the active region, achieves a more balanced carrier concentration, enhances radiative recombination of deep ultraviolet LEDs, promotes photon recycling, improves photoelectric conversion efficiency, and thus improves the overall luminous efficiency of deep ultraviolet LEDs, allowing more deep ultraviolet light to escape into the air. The method of this invention is highly operable, simple in process, low in cost, and easy to implement.
[0078] All raw materials involved in this invention can be obtained through known means, and the operation process in its preparation method is mastered by those skilled in the art.
[0079] Matters not covered in this invention are common knowledge.
Claims
1. A deep ultraviolet light-emitting diode with a patterned photon absorption structure, characterized in that, The diode comprises, from bottom to top, a substrate, an AlN buffer layer, and an N-type AlGaN layer; one side of the N-type AlGaN layer is exposed; the upper surface of the unexposed N-type AlGaN layer is covered from bottom to top with a multi-quantum well layer, a P-type electron blocking layer, a P-type AlGaN layer, and a P-type GaN layer; an oxide nanostructure is arrayed on the upper surface of the P-type GaN layer; a P-type ohmic contact layer is covered on the oxide nanostructure and the P-type GaN layer, also forming an arrayed structure; The metal mirror electrode is covered on a P-type ohmic contact layer; N-type ohmic electrodes are also distributed on the surface of the exposed portion of the N-type AlGaN layer; The exposed area of the N-type AlGaN layer is 5% to 90% of the total surface area of the N-type AlGaN layer; the height of the exposed portion is 5% to 90% of the total height of the N-type AlGaN layer. The oxide nanostructure is made of n-type ZnO or n-type Ga2O3, with a doping concentration of 1*10e15-1*10e20 / cm³. 3 The thickness is between 5 and 500 nm; The oxide nanostructure is a nanopillar array with a diameter of 10 nm to 10,000 nm and a spacing of 10 nm to 10,000 nm between the nanopillars; the fill factor is 20% to 80%. The substrate is a C-plane sapphire substrate; The buffer layer material is AlN, and the thickness is 1~3μm; The N-type AlGaN layer material is Al 0.6 Ga 0.4 N, with a thickness of 1~3μm; The structure of the multi-quantum well layer is a 5-period Al 0.45 Ga 0.55 N / Al 0.56 Ga 0.44 N layers, where the quantum barrier Al 0.56 Ga 0.44 The thickness of N is set to 11~12nm, and the quantum well Al 0.45 Ga 0.55 The thickness of N is set to 3~4nm; The P-type electron blocking layer material is Al 0.6 Ga 0.4 N, with a thickness of 10~50nm; The p-type AlGaN layer material is Al 0.4 Ga 0.6 N, with a thickness of 50~200nm; The thickness of the p-type GaN layer is 10~50nm; The material of the P-type ohmic contact layer is Ni / Au or Ni / Al; The material of the metal reflector electrode is Al; The N-type ohmic electrode is made of Cr / Au or Ti / Al / Ti / Au, wherein the projected area of the N-type ohmic electrode is 10 to 80% of the area of the exposed N-type AlGaN layer.
2. The method for fabricating a deep ultraviolet light-emitting diode with a patterned photon absorption structure as described in claim 1, characterized in that, Includes the following steps: The first step is to bake the substrate at 1250–1350°C in an MOCVD (metal-organic chemical vapor deposition) or MBE (molecular beam epitaxy) furnace to remove foreign matter from the substrate surface. Then, an AlN buffer layer, an N-type AlGaN layer, a multiple quantum well layer, a P-type electron blocking layer, a P-type AlGaN layer, and a P-type GaN layer are sequentially grown on the sapphire substrate. The second step is to spin-coat a positive photoresist layer onto the P-type GaN layer obtained in the first step. The third step is to attach a single layer of nanosphere lens layer onto the photoresist layer obtained in the second step. The fourth step involves fabricating a photoresist nanostructure on the nanosphere lens layer obtained in the third step using exposure and development processes. The fifth step involves growing an oxide structure on the photoresist nanostructure obtained in the fourth step using magnetron sputtering. The sixth step involves removing the photoresist mask and the oxides on it using a stripping technique to obtain the oxide nanostructure. The seventh step involves fabricating a mesa using photolithography and dry etching processes. This process involves etching oxide nanostructures, P-type GaN layers, P-type AlGaN layers, P-type electron blocking layers, multiple quantum well layers, and N-type AlGaN layers to form a DUV LED epitaxial layer structure that passes through the quantum well structure, and exposing 5-90% of the N-type AlGaN layer. The eighth step involves fabricating a mask for the P-type ohmic contact layer using photolithography, exposing 30-100% of the area in the middle of the P-GaN mesa surface. The P-type ohmic contact layer is then deposited using electron beam evaporation or magnetron sputtering. Afterward, the mask and the P-type ohmic contact layer on the mask are stripped off. The ninth step involves depositing and photolithographically fabricating an N-type ohmic electrode on the exposed N-type AlGaN layer, with an area of 10–80% of the exposed N-type AlGaN layer area. Step 10: Deposit the metal mirror electrode onto the exposed P-type ohmic contact layer.