CN111697113A - Preparation method of Micro-LED device and Micro-LED device - Google Patents

Abstract

Embodiments of the present invention disclose a preparation method of a Micro-LED device and a Micro-LED device, wherein the preparation method includes: forming an epitaxial layer, and the epitaxial layer includes a first N-type semiconductor layer and a second N-type semiconductor layer disposed on a substrate. The semiconductor layer, the quantum well layer, the P-type semiconductor layer and the current spreading layer; the epitaxial layer is processed by plasma; the same family interface layer is formed, and the same family interface layer covers the second N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer and the The side surface of the current spreading layer, and the non-electrode area on the upper surface of the current spreading layer and the first N-type semiconductor layer; forming an electrode covering the current spreading layer and the electrode area on the upper surface of the first N-type semiconductor layer. The technical solutions provided by the embodiments of the present invention reduce the formation of sidewall surface states and the density of surface defects of the device, thereby improving the luminous efficiency of the device and ensuring the working characteristics of the device.

Description

A kind of preparation method of Micro-LED device and Micro-LED device

technical field

Embodiments of the present invention relate to the technical field of semiconductor device fabrication, and in particular, to a method for fabricating a Micro-LED device and a Micro-LED device.

Background technique

Micro-LED display is an array display technology composed of micron-scale LED light-emitting pixels integrated on an active addressing drive substrate, which has the advantages of high efficiency, low power consumption, high integration, and high stability. Among many new display technologies, Micro-LED display is considered to be a disruptive next-generation display technology. The core of Micro-LED display technology is Micro-LED devices with dimensions less than 50 microns. The technical bottleneck faced by Micro-LED devices at present is that their peak efficiency decreases as the device size decreases. As the size of Micro-LED devices decreases from 500 microns to 10 microns, the peak luminous efficiency attenuates by about 50%. This is due to the fact that during the preparation process of the device, the etching process introduces lattice damage to the sidewall of the Micro-LED, and surface states such as dangling bonds, nitrogen vacancies, oxide layers and surface defects exist on the sidewall surface, so the micro-LED side The wall introduces a large number of surface defect levels, which reduces the luminous efficiency of the device. It can be seen that the effect of surface states on the efficiency of Micro-LED devices increases significantly with decreasing device size.

At present, the sidewall passivation process of Micro-LED devices mainly uses plasma-enhanced chemical vapor epitaxy or atomic layer deposition equipment to deposit insulating layers such as silicon oxide or aluminum oxide on the sidewalls of Micro-LEDs. Although this passivation process can effectively passivate the sidewall surface and reduce the density of dangling bonds on the sidewall surface, for Micro-LED devices, this process does not effectively improve the nitrogen vacancies, oxide layers and surface defects of Micro-LED devices However, the effect of surface states on the efficiency of Micro-LED devices remains unresolved.

SUMMARY OF THE INVENTION

The embodiments of the present invention provide a preparation method of a Micro-LED device and a Micro-LED device, so as to effectively prevent the formation of sidewall surface states, reduce the influence of the surface states on the Micro-LED device, and improve the luminous efficiency of the Micro-LED device, Guaranteed device operating characteristics.

In a first aspect, an embodiment of the present invention provides a method for preparing a Micro-LED device, including:

An epitaxial layer is formed, the epitaxial layer includes a first N-type semiconductor layer, a second N-type semiconductor layer, a quantum well layer, a P-type semiconductor layer and a current spreading layer disposed on a substrate, the second N-type semiconductor layer , the quantum well layer, the P-type semiconductor layer and the current spreading layer are stacked and arranged, and cover part of the first N-type semiconductor layer;

treating the epitaxial layer by plasma;

forming a same-family interface layer; the same-family interface layer covers the side surfaces of the second N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer and the current spreading layer, and the current spreading layer and the the non-electrode region on the upper surface of the first N-type semiconductor layer;

forming electrodes; the electrodes cover the current spreading layer and the electrode regions on the upper surface of the first N-type semiconductor layer.

Optionally, before the treatment of the epitaxial layer by plasma further includes:

Remove the etching damage on the sidewall of the epitaxial layer by potassium hydroxide solution;

The first oxidation product on the sidewalls of the epitaxial layer is removed by a hydrogen chloride solution.

Optionally, the processing of the epitaxial layer by plasma includes:

forming a first plasma by plasma enhanced atomic layer deposition equipment, and passing through the first plasma to remove the second oxidation product on the sidewall of the epitaxial layer;

A second plasma is formed by a plasma-enhanced atomic layer deposition apparatus, and the second plasma fills nitrogen vacancies in the sidewalls of the epitaxial layer and improves the interface quality of the sidewalls.

Optionally, the first plasma is formed based on ammonia gas and/or a mixed gas of nitrogen gas and hydrogen gas; the second plasma is formed based on ammonia gas and/or nitrogen gas.

Optionally, the first plasma and the second plasma further treat the surface based on argon gas as an auxiliary gas.

Optionally, the forming the interface layer of the same family includes:

Aluminum nitride is deposited by plasma enhanced atomic layer deposition equipment; wherein the aluminum source is trimethylaluminum, and the nitrogen source is plasma of a mixture of nitrogen and hydrogen.

Optionally, after forming the interface layer of the same family, the method further includes:

An insulating layer is formed on the same-family interface layer.

Optionally, the forming an insulating layer on the interface layer of the same family includes:

Aluminum oxide is deposited by plasma enhanced atomic layer deposition equipment; wherein the aluminum source is trimethylaluminum, and the oxygen source is water.

In a second aspect, an embodiment of the present invention provides a Micro-LED device, including:

an epitaxial layer, the epitaxial layer includes a first N-type semiconductor layer, a second N-type semiconductor layer, a quantum well layer, a P-type semiconductor layer and a current spreading layer arranged on a substrate, the second N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer and the current spreading layer are stacked and arranged to cover part of the first N-type semiconductor layer;

an interface layer of the same family covering the side surfaces of the second N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer and the current spreading layer, and the current spreading layer and the first The non-electrode region on the upper surface of the N-type semiconductor layer;

and an electrode covering the current spreading layer and the electrode region on the upper surface of the first N-type semiconductor layer.

Optionally, the Micro-LED device further includes an insulating layer, and the insulating layer covers the interface layer of the same family.

Embodiments of the present invention provide a method for preparing a Micro-LED device and a Micro-LED device, wherein the method for preparing a Micro-LED device includes: forming an epitaxial layer, and the epitaxial layer includes a first N-type semiconductor layer disposed on a substrate , the second N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer and the current spreading layer, the second N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer and the current spreading layer are stacked and arranged to cover part of the first N-type The semiconductor layer; the epitaxial layer is processed by plasma; the same-family interface layer is formed, and the same-family interface layer covers the side surfaces of the second N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer and the current spreading layer, as well as the current spreading layer and the first semiconductor layer; A non-electrode area on the upper surface of the N-type semiconductor layer; forming an electrode, the electrode covers the current spreading layer and the electrode area on the upper surface of the first N-type semiconductor layer. The technical solutions provided by the embodiments of the present invention are aimed at the cause of the formation of the surface state of the sidewall of the Micro-LED. By adopting the surface treatment process and the interfacial layer of the same family inserted, the formation of the surface state of the sidewall can be effectively reduced, and the surface defect density of the Micro-LED can be reduced. Thus, the luminous efficiency of the Micro-LED device is improved, and the working characteristics of the device are ensured.

Description of drawings

FIG. 1 is a flowchart of a method for preparing a Micro-LED device provided in Embodiment 1 of the present invention;

2 to 13 are structural cross-sectional views of each step in a method for preparing a Micro-LED device provided in Embodiment 1 of the present invention;

14 is a flow chart of a method for preparing a Micro-LED device provided in Embodiment 2 of the present invention;

15 is a schematic diagram of processing an epitaxial layer by a first plasma according to Embodiment 2 of the present invention;

16 is a schematic diagram of processing an epitaxial layer by a second plasma according to Embodiment 2 of the present invention;

FIG. 17 is a structural cross-sectional view of a Micro-LED device according to the second embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for the convenience of description, the drawings only show some but not all structures related to the present invention.

Example 1

An embodiment of the present invention provides a method for fabricating a Micro-LED device. FIG. 1 is a flowchart of a method for fabricating a Micro-LED device according to Embodiment 1 of the present invention. FIGS. 2 to 13 are Embodiment 1 of the present invention. Provided is a cross-sectional view of the structure of each step in the preparation method of a Micro-LED device, referring to Figures 1-13, the preparation method includes:

S110, forming an epitaxial layer, the epitaxial layer includes a first N-type semiconductor layer, a second N-type semiconductor layer, a quantum well layer, a P-type semiconductor layer and a current spreading layer disposed on the substrate, the second N-type semiconductor layer, the quantum The well layer, the P-type semiconductor layer and the current spreading layer are stacked and arranged to cover part of the first N-type semiconductor layer.

Specifically, referring to FIG. 2 , an N-type semiconductor layer 20 , a quantum well layer 30 and a P-type semiconductor layer 40 are sequentially formed on the substrate 10 . Referring to FIG. 3, a current spreading layer 50 is deposited on the p-type semiconductor layer 40, and an annealing process is performed to make it a p-type current spreading layer. The substrate 10 can be a sapphire substrate; the N-type semiconductor layer 20 can be set as an n-GaN layer; the quantum well layer 30 can be set as an InGaN/GaN layer, and the P-type semiconductor layer 40 can be set as a P-GaN layer; The layer 50 can be set as an ITO (Indium Tin Oxide, indium tin oxide) layer. ITO is an N-type oxide semiconductor-indium tin oxide, which has a certain resistance and light transmittance. The ITO layer is used as a transparent conductive film, which can Reduce the harmful electronic radiation of Micro-LED devices to the human body.

Referring to FIG. 4 , a silicon oxide layer 60 is deposited on the current spreading layer 50 with a thickness of 200 nm. Further, referring to FIG. 5 , photolithography is performed on the surface of the silicon oxide layer 60 to form a first photoresist mask 70 , so that the first photoresist mask 70 covers the area that needs to be reserved. Further, referring to FIG. 6 , using RIE (Reactive Ion Etching, reactive ion etching) equipment, using the first photoresist mask 70 as a mask, the silicon oxide layer 60 is etched by plasma of CHF ₃ and O ₂ , The pattern of photoresist is transferred to the silicon oxide layer 60, and the residual photoresist on the surface is removed. Further, referring to FIGS. 7-8 , using ICP (Inductively Coupled Plasma) equipment, using the silicon oxide layer 60 on the surface as a mask, the current spreading layer 50 is sequentially applied to the current spreading layer 50 by the plasma of Cl ₂ and Cl ₃ B , P-type semiconductor layer 40, quantum well layer 30 and part of N-type semiconductor layer 20 are etched to form second N-type semiconductor layer 21, quantum well layer 30, P-type semiconductor layer 40 and current spreading layer 50 are stacked and arranged Parts of the mesa structures of the first N-type semiconductor layer 21 are covered.

S120, treating the epitaxial layer by plasma.

Specifically, in step S110, ICP equipment is used to etch the epitaxial layer, and surface states such as dangling bonds, nitrogen vacancies, oxide layers, and surface defects may exist on the sidewall surface after the epitaxial layer is etched, so that the sidewall of the Micro-LED has surface states such as dangling bonds, nitrogen vacancies, oxide layers, and surface defects. A large number of surface defect levels are introduced, resulting in a decrease in the luminous efficiency of the device. Referring to FIG. 9 , in step S120 , for the main cause of the efficiency attenuation of the Micro-LED device, PEALD (Plasma Enhanced Chemical Vapor Deposition, plasma enhanced chemical vapor deposition) equipment can be used to utilize the high chemical activity of the remote plasma 3 on the sidewall surface of the epitaxial layer 2 Surface treatment. The gas G is introduced into the PEALD equipment, and the gas G passes through the radio frequency coil 1 of the PEALD equipment to generate ions 3. The oxide layer on the sidewall surface can be removed and the nitrogen vacancies can be filled by treating the epitaxial layer 2 with the plasma 3, which can effectively reduce the The formation of sidewall surface states improves the luminous efficiency of the Micro-LED device and ensures the device operating characteristics.

S130, forming an interface layer of the same family; the interface layer of the same family covers the side surfaces of the second N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer and the current spreading layer, and the non-electrodes on the upper surface of the current spreading layer and the first N-type semiconductor layer area.

Specifically, referring to FIG. 10, PEALD equipment is used on the side surfaces of the second N-type semiconductor layer 22, the quantum well layer 30, the P-type semiconductor layer 40 and the current spreading layer 50, as well as the current spreading layer 50 and the first N-type semiconductor layer. 21 In situ deposition of the same family interface layer 80 as the Micro-LED same family on the upper surface. The elements in the material of the interface layer 80 of the same family are of the same family as the gallium element in the epitaxial layer, and have similar chemical properties. Therefore, on the sidewall after the epitaxial layer is etched, that is, the second N-type semiconductor layer 22, the quantum well layer 30, the P The side surfaces of the N-type semiconductor layer 40 and the current spreading layer 50, as well as the upper surfaces of the current spreading layer 50 and the first N-type semiconductor layer 21, are deposited with an interface layer of the same family, so that the interface layer of the same family can be connected to the sidewall after the epitaxial layer is etched Up, reduce the dangling keys on the side wall and play a passivation role. The formation of the sidewall surface states is further reduced, the luminous efficiency of the Micro-LED device is improved, and the working characteristics of the device are ensured.

Since electrodes need to be formed on the electrode region L on the upper surface of the current spreading layer 50 and the first N-type semiconductor layer 21, the sidewalls after epitaxial layer etching, namely the second N-type semiconductor layer 22, the quantum well layer 30, P After depositing a same-family interface layer 80 on the side surfaces of the current spreading layer 40 and the current spreading layer 50, and the upper surfaces of the current spreading layer 50 and the first N-type semiconductor layer 21, it needs to be located between the current spreading layer 50 and the first N-type semiconductor layer 21. The interface layer 80 of the same family in the electrode region L on the upper surface of the layer 21 is provided with a window to realize the contact of the electrode with the current spreading layer and the first N-type semiconductor layer. Referring to FIG. 11 , a second photoresist mask 100 is formed on the surface of the epitaxial layer, and the current spreading layer 50 and the window of the upper surface electrode region L of the first N-type semiconductor layer 21 are opened by a photolithography process. Referring to FIG. 12 , the second photoresist mask 100 is used as a mask, and the epitaxial layer is further etched by ICP to remove the current spreading layer 50 and the same family interface layer of the electrode region L on the upper surface of the first N-type semiconductor layer 21 80.

It should be noted that both the plasma treatment of the epitaxial layer in step S120 and the formation of the same family interface layer in step S130 can be completed in the PEALD equipment, that is, the same family interface layer of the same family as the Micro-LED is deposited in-situ in this step S130, thereby It can be avoided that the treated epitaxial layer is oxidized again or polluted by the external environment due to the use of different equipment.

S140 , forming an electrode; the electrode covers the current spreading layer and the electrode region on the upper surface of the first N-type semiconductor layer.

Specifically, referring to FIG. 13 , electrodes are formed. The electrode located in the electrode region L on the current spreading layer 50 is the P electrode 110 , and the electrode located in the electrode region L on the first N-type semiconductor layer 21 is the N electrode 120 . Each electrode is formed by four metal layers, and the corresponding metals are titanium, aluminum, titanium and gold in turn.

The preparation method of the Micro-LED device provided by the embodiment of the present invention includes: forming an epitaxial layer, and the epitaxial layer includes a first N-type semiconductor layer, a second N-type semiconductor layer, a quantum well layer, and a P-type semiconductor layer disposed on a substrate. layer and current spreading layer, the second N-type semiconductor layer, quantum well layer, P-type semiconductor layer and current spreading layer are stacked and arranged, and cover part of the first N-type semiconductor layer; the epitaxial layer is processed by plasma; the same family interface is formed layer, the same family interface layer covers the side surfaces of the second N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer and the current spreading layer, as well as the non-electrode regions of the current spreading layer and the upper surface of the first N-type semiconductor layer; forming electrodes, The electrode covers the current spreading layer and the electrode region on the upper surface of the first N-type semiconductor layer. The technical solutions provided by the embodiments of the present invention are aimed at the cause of the formation of the surface state of the sidewall of the Micro-LED. By adopting the surface treatment process and the interfacial layer of the same family inserted, the formation of the surface state of the sidewall can be effectively reduced, and the surface defect density of the Micro-LED can be reduced. Thus, the luminous efficiency of the Micro-LED device is improved, and the working characteristics of the device are ensured.

Embodiment 2

The embodiment of the present invention provides a preparation method of a Micro-LED device. On the basis of the above-mentioned first embodiment, the embodiment of the present invention supplements and refines the preparation method. Wherein, before the treatment of the epitaxial layer by plasma further includes: removing the etching damage on the sidewall of the epitaxial layer by using a potassium hydroxide solution; removing the first oxidation product on the sidewall of the epitaxial layer by using a hydrogen chloride solution. After forming the same-family interface layer, the method further includes: forming an insulating layer on the same-family interface layer. In addition, the processing of the epitaxial layer by plasma includes: forming a first plasma by plasma enhanced atomic layer deposition equipment, and passing the first plasma to remove the second oxidation product of the sidewall of the epitaxial layer; enhancing the plasma The atomic layer deposition apparatus forms a second plasma, and fills the nitrogen vacancies in the sidewalls of the epitaxial layer by the second plasma.

A preparation method of a Micro-LED device, FIG. 14 is a flow chart of a preparation method of a Micro-LED device provided in Embodiment 2 of the present invention, with reference to FIG. 14 , the preparation method includes:

S210, forming an epitaxial layer, the epitaxial layer includes a first N-type semiconductor layer, a second N-type semiconductor layer, a quantum well layer, a P-type semiconductor layer, and a current spreading layer disposed on the substrate, the second N-type semiconductor layer, the quantum The well layer, the P-type semiconductor layer and the current spreading layer are stacked and arranged to cover part of the first N-type semiconductor layer.

S220, removing the etching damage on the sidewall of the epitaxial layer by using a potassium hydroxide solution.

Specifically, using ICP (Inductively Coupled Plasma, Inductively Coupled Plasma) equipment, using the surface silicon oxide layer as a mask, the current spreading layer, the P-type semiconductor layer, the quantum well layer and the second N-type semiconductor layer are sequentially etched Then, dangling bonds, nitrogen vacancies, oxide layers and surface defects may exist on the sidewall surface after the epitaxial layer is etched. The etching damage on the sidewall of the epitaxial layer can be removed by potassium hydroxide solution, so as to avoid the influence of surface defects in the surface state on reducing the luminous efficiency of the Micro-LED device, and further improve the luminous efficiency of the Micro-LED device. Exemplarily, immersing the epitaxial layer in a potassium hydroxide solution with a concentration range of 0.5 mol/L to 2 mol/L and a temperature range of 40 ℃ to 80 ℃ for 30 minutes can remove the etching damage on the sidewall of the epitaxial layer, leaving the ideal lattice. It is worth noting that after removing the etch damage on the sidewall of the epitaxial layer by potassium hydroxide solution, the epitaxial layer needs to be rinsed with deionized water to remove other impurities.

S230 , removing the first oxidation product on the sidewall of the epitaxial layer by using a hydrogen chloride solution.

Specifically, in the process of removing the etching damage on the sidewall of the epitaxial layer by the potassium hydroxide solution, a first oxidation product will remain on the sidewall of the epitaxial layer, and the first oxidation product is mainly GaO ₂ . The first oxidation product on the sidewall of the epitaxial layer can be removed by reacting the hydrogen chloride solution, ie, dilute hydrochloric acid, with the first oxidation product. The hydrogen chloride solution, that is, the reaction time between dilute hydrochloric acid and the first oxidation product, is maintained for 2 to 3 minutes to immediately remove the first oxidation product on the sidewall of the epitaxial layer. If there are many first oxidation products, the reaction time can be appropriately extended. It is worth noting that, after the first oxidation product on the sidewall of the epitaxial layer is removed by the hydrogen chloride solution, the epitaxial layer needs to be rinsed with deionized water to remove other impurities, and finally the epitaxial layer is dried. Removing the oxide layer formed by the first oxidation product on the sidewall of the epitaxial layer by the hydrogen chloride solution can effectively reduce the formation of the surface state of the sidewall, thereby further improving the luminous efficiency of the Micro-LED device and ensuring the device operating characteristics.

S240 , using a plasma enhanced atomic layer deposition apparatus to form a first plasma, and using the first plasma to remove the second oxidation product on the sidewall of the epitaxial layer.

Specifically, during the process of placing the dried epitaxial layer in the plasma enhanced atomic layer deposition equipment, after the epitaxial layer is in contact with the outside air, an oxide, ie, a second oxidation product, will be generated on the surface of the epitaxial layer again. FIG. 15 is a schematic diagram of processing an epitaxial layer by a first plasma according to Embodiment 2 of the present invention. Referring to FIG. 15 and in conjunction with FIG. 9 , a first plasma C is formed by a plasma enhanced atomic layer deposition apparatus, and the The first plasma C is used to remove the second oxidation product on the sidewall of the epitaxial layer. Optionally, the first plasma C is formed based on ammonia gas and/or a mixed gas of nitrogen gas and hydrogen gas. The ammonia gas is passed into the PEALD equipment, or the mixed gas of nitrogen and hydrogen is passed into the PEALD equipment, or the mixed gas of ammonia, nitrogen and hydrogen can also be passed into the PEALD equipment. The gas G generates a first plasma C after passing through the radio frequency coil 1 of the PEALD device. It is worth noting that the position where the first plasma C is generated is different from that of the epitaxial layer. The first plasma C diffuses to the surface of the epitaxial layer, and processes the sidewall of the epitaxial layer to remove the second oxidation product on the sidewall of the epitaxial layer. The first plasma C formed by the plasma enhanced atomic layer deposition equipment removes the oxide layer formed by the second oxidation product on the sidewall of the epitaxial layer, which can effectively reduce the formation of surface states on the sidewall, thereby further improving the luminous efficiency of the Micro-LED device , to ensure the device operating characteristics.

S250 , forming a second plasma by using a plasma enhanced atomic layer deposition apparatus, and filling nitrogen vacancies in the sidewall of the epitaxial layer and improving the interface quality of the sidewall by using the second plasma.

Specifically, FIG. 16 is a schematic diagram of processing the epitaxial layer by the second plasma according to the second embodiment of the present invention. Referring to FIG. 16 , in conjunction with FIG. 9 , after the epitaxial layer is processed by the first plasma C, the The plasma enhanced atomic layer deposition equipment forms a second plasma D, and fills the nitrogen vacancies in the sidewall of the epitaxial layer by the second plasma D, thereby reducing the density of nitrogen vacancies in the sidewall of the epitaxial layer. Optionally, the second plasma D is formed based on ammonia and/or nitrogen. The ammonia gas is passed into the PEALD equipment, or the nitrogen gas is passed into the PEALD equipment, or the mixed gas of ammonia gas and nitrogen gas is passed into the PEALD equipment. After the gas G passes through the radio frequency coil 1 of the PEALD equipment, a second plasma D is generated. The second plasma D is nitrogen plasma. The sidewall of the Micro-LED is nitrided with nitrogen plasma to improve the interface quality of the sidewall. The second plasma D formed by the plasma-enhanced atomic layer deposition equipment fills the nitrogen vacancies on the sidewall of the epitaxial layer, reduces the density of nitrogen vacancies on the sidewall of the epitaxial layer, and can effectively reduce the formation of surface states on the sidewall, thereby further improving the The luminous efficiency of the Micro-LED device is improved, and the working characteristics of the device are guaranteed.

S260, forming an interface layer of the same family; the interface layer of the same family covers the side surfaces of the second N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer and the current spreading layer, as well as the non-electrodes on the upper surface of the current spreading layer and the first N-type semiconductor layer area.

Optionally, forming the interface layer of the same family includes: depositing aluminum nitride by plasma enhanced atomic layer deposition equipment; wherein the aluminum source is trimethyl aluminum, and the nitrogen source is plasma of a mixture of nitrogen and hydrogen.

Specifically, in the PEALD device, in-situ growth of a second N-type semiconductor layer, a quantum well layer, a P-type semiconductor layer and a side surface of the current spreading layer of the epitaxial layer, as well as the upper surfaces of the current spreading layer and the first N-type semiconductor layer Homogeneous interface layer of the same family of nitrides. Homologous interface layers may be formed by depositing a layer of aluminum nitride. Aluminum and gallium are elements of the same family, which can reduce the density of states at the interface. The inserted interfacial layer of the same family effectively reduces the surface defect density of the Micro-LED, thereby improving the luminous efficiency of the Micro-LED device. The aluminum source is trimethylaluminum, and the nitrogen source is a plasma of a mixture of nitrogen and hydrogen. A 1:1 mixture of nitrogen and hydrogen can form a plasma at room temperature. Ammonia plasma can also be selected as the nitrogen source, but the plasma needs to be formed at a high temperature.

S270 , forming an insulating layer on the interface layer of the same family.

Optionally, FIG. 17 is a structural cross-sectional view of a Micro-LED device according to Embodiment 2 of the present invention. Referring to FIG. 17 , an insulating layer 90 may also be formed on the interface layer 80 of the same family. Aluminum oxide is deposited by plasma enhanced atomic layer deposition equipment; wherein the aluminum source is trimethylaluminum, and the oxygen source is water. Trimethylaluminum and water can directly react to form alumina, and it is not necessary to generate plasma before forming alumina. Forming the insulating layer 90 can effectively passivate the sidewall surface and further reduce the density of dangling bonds on the sidewall surface.

S280 , forming an electrode; the electrode covers the current spreading layer and the electrode region on the upper surface of the first N-type semiconductor layer.

Specifically, continue to refer to FIG. 17 , the epitaxial layer is etched by ICP to remove the same family interface layer 80 and insulating layer 90 in the P electrode and N electrode regions. Repeat. Electrodes are prepared in the above-mentioned P electrode and N electrode regions, wherein the electrode located in the electrode region L on the current spreading layer 50 is the P electrode 110, and the electrode located in the electrode region L on the first N-type semiconductor layer 21 is the N electrode 120. The electrodes are formed by four metal layers, and the corresponding metals are titanium, aluminum, titanium and gold in turn.

Optionally, in step S240 and step S250, argon gas may also be introduced at the same time when the gas is introduced, and the first plasma and the second plasma also process the surface based on argon gas as an auxiliary gas.

The preparation method of the Micro-LED device provided by the embodiment of the present invention. Wherein, before the treatment of the epitaxial layer by plasma further includes: removing the etching damage on the sidewall of the epitaxial layer by using a potassium hydroxide solution; removing the first oxidation product on the sidewall of the epitaxial layer by using a hydrogen chloride solution. After forming the same-family interface layer, the method further includes: forming an insulating layer on the same-family interface layer. In addition, the processing of the epitaxial layer by plasma includes: forming a first plasma by plasma enhanced atomic layer deposition equipment, and passing the first plasma to remove the second oxidation product of the sidewall of the epitaxial layer; enhancing the plasma The atomic layer deposition apparatus forms a second plasma, and fills the nitrogen vacancies in the sidewalls of the epitaxial layer by the second plasma. According to the technical solutions provided by the embodiments of the present invention, according to the origin of the surface defects of the sidewall of the epitaxial layer, PEALD equipment is used in a targeted manner, and the high chemical activity of the remote plasma is used to first perform surface treatment on the surface of the sidewall of the epitaxial layer, and deposit in situ. The interface layer of the same family is further deposited with an aluminum oxide insulating layer. The surface treatment process and the interfacial layer of the same family inserted in this method can effectively reduce the surface defect density of the Micro-LED, thereby improving the luminous efficiency of the Micro-LED device.

Embodiment 3

An embodiment of the present invention provides a Micro-LED device. Referring to FIG. 13 , the device includes:

Epitaxial layer, the epitaxial layer includes a first N-type semiconductor layer 21 , a second N-type semiconductor layer 22 , a quantum well layer 30 , a P-type semiconductor layer 40 and a current spreading layer 50 arranged on the substrate 10 , the second N-type semiconductor layer 50 The layer 22, the quantum well layer 30, the P-type semiconductor layer 40 and the current spreading layer 50 are stacked and arranged, and cover part of the first N-type semiconductor layer 21;

The same family interface layer 80 covers the side surfaces of the second N-type semiconductor layer 22 , the quantum well layer 30 , the P-type semiconductor layer 40 and the current spreading layer 50 , and the current spreading layer 50 and the first N-type semiconductor layer 21 non-electrode areas on the upper surface;

The electrode covers the current spreading layer 50 and the electrode region on the upper surface of the first N-type semiconductor layer 21 . The electrode located on the current spreading layer 50 is the P electrode 110, and the electrode located on the first N-type semiconductor layer 21 is the N electrode 120

Optionally, referring to FIG. 17 , the Micro-LED device further includes insulation 90 , and the insulation layer 90 covers the interface layer 80 of the same family.

The Micro-LED device provided by the embodiment of the present invention includes an epitaxial layer, a homologous interface layer and an electrode. Wherein, the epitaxial layer includes a first N-type semiconductor layer, a second N-type semiconductor layer, a quantum well layer, a P-type semiconductor layer and a current spreading layer disposed on the substrate, the second N-type semiconductor layer, the quantum well layer , a P-type semiconductor layer and a current spreading layer are stacked and arranged to cover part of the first N-type semiconductor layer; the same family interface layer covers the side surfaces of the second N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer and the current spreading layer, and The current spreading layer and the non-electrode area on the upper surface of the first N-type semiconductor layer; the electrode covers the current spreading layer and the electrode area on the upper surface of the first N-type semiconductor layer. The surface state of the Micro-LED device is reduced and the luminous efficiency of the Micro-LED device is improved by the surface treatment process and the intercalated interfacial layer of the same family.

Note that the above are only preferred embodiments of the present invention and applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present invention. The scope is determined by the scope of the appended claims.

Claims (10)

1. a preparation method of Micro-LED device, is characterized in that, comprises: An epitaxial layer is formed, the epitaxial layer includes a first N-type semiconductor layer, a second N-type semiconductor layer, a quantum well layer, a P-type semiconductor layer and a current spreading layer disposed on a substrate, the second N-type semiconductor layer , the quantum well layer, the P-type semiconductor layer and the current spreading layer are stacked and arranged, and cover part of the first N-type semiconductor layer; treating the epitaxial layer by plasma; forming a same-family interface layer; the same-family interface layer covers the side surfaces of the second N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer and the current spreading layer, and the current spreading layer and the the non-electrode region on the upper surface of the first N-type semiconductor layer; forming electrodes; the electrodes cover the current spreading layer and the electrode regions on the upper surface of the first N-type semiconductor layer. 2 . The method for preparing a Micro-LED device according to claim 1 , wherein before the treatment of the epitaxial layer by plasma, the method further comprises: 3 . Remove the etching damage on the sidewall of the epitaxial layer by potassium hydroxide solution; The first oxidation product on the sidewalls of the epitaxial layer is removed by a hydrogen chloride solution. 3 . The method for preparing a Micro-LED device according to claim 1 , wherein the processing of the epitaxial layer by plasma comprises: 4 . forming a first plasma by plasma enhanced atomic layer deposition equipment, and passing through the first plasma to remove the second oxidation product on the sidewall of the epitaxial layer; A second plasma is formed by a plasma-enhanced atomic layer deposition apparatus, and the second plasma fills nitrogen vacancies in the sidewalls of the epitaxial layer and improves the interface quality of the sidewalls. 4. The preparation method of Micro-LED device according to claim 3, wherein, The first plasma is formed based on ammonia and/or a mixed gas of nitrogen and hydrogen; The second plasma is formed based on ammonia and/or nitrogen. 5 . The method for manufacturing a Micro-LED device according to claim 4 , wherein the first plasma and the second plasma further treat the surface based on argon gas as an auxiliary gas. 6 . 6 . The method for preparing a Micro-LED device according to claim 1 , wherein the forming the interface layer of the same family comprises: Aluminum nitride is deposited by plasma enhanced atomic layer deposition equipment; wherein the aluminum source is trimethylaluminum, and the nitrogen source is plasma of a mixture of nitrogen and hydrogen. 7 . The method for preparing a Micro-LED device according to claim 1 , wherein after forming the interface layer of the same family, the method further comprises: 8 . An insulating layer is formed on the same-family interface layer. 8. The method for preparing a Micro-LED device according to claim 7, wherein the forming an insulating layer on the interface layer of the same family comprises: Aluminum oxide is deposited by plasma enhanced atomic layer deposition equipment; wherein the aluminum source is trimethylaluminum, and the oxygen source is water. 9. A Micro-LED device, characterized in that, comprising: an epitaxial layer, the epitaxial layer includes a first N-type semiconductor layer, a second N-type semiconductor layer, a quantum well layer, a P-type semiconductor layer and a current spreading layer arranged on a substrate, the second N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer and the current spreading layer are stacked and arranged to cover part of the first N-type semiconductor layer; a homologous interface layer covering the side surfaces of the second N-type semiconductor layer, the quantum well layer, the P-type semiconductor layer and the current spreading layer, and the current spreading layer and the first The non-electrode region on the upper surface of the N-type semiconductor layer; and an electrode covering the current spreading layer and the electrode region on the upper surface of the first N-type semiconductor layer. 10 . The Micro-LED device according to claim 9 , further comprising an insulating layer covering the same-family interface layer. 11 .

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