Method and machine for manufacturing micro-light-emitting diodes capable of reducing non-radiative recombination

Abstract

The present invention is a method for manufacturing a micro-LED that reduces non-radiative recombination, and provides an etched LED epitaxial wafer, wherein the etched LED epitaxial wafer includes a plurality of etched grooves and a plurality of platform structures, and an etched side wall of the platform structure includes a stack of a first-type semiconductor layer, an active layer, and a second-type semiconductor layer. The etched LED epitaxial wafer is subjected to two-stage atomic layer deposition, wherein the temperature ranges of the two stages of atomic layer deposition are different. The first atomic layer deposition can be used to repair suspended bonds and defects on the etched side wall of the platform structure, and the second atomic layer deposition is used to form a passivation layer on the etched side wall of the platform structure. The manufacturing method described in the present invention can reduce the non-radiative recombination of the micro-LED, and can effectively improve the luminous brightness and luminous efficiency of the micro-LED.

Description

Technical Field

[0001] The present invention relates to a method and a machine for manufacturing a micro-LED capable of reducing non-radiative recombination, which can reduce the non-radiative recombination of the micro-LED and effectively improve the luminous brightness and luminous efficiency of the micro-LED. Background Art

[0002] Light-emitting diodes have the advantages of high conversion efficiency, long service life, small size and high safety, and have become a new generation of lighting sources. In addition, light-emitting diodes have also replaced traditional cold cathode tubes as the backlight source of display panels, and are particularly suitable for small portable electronic devices such as notebook computers, mobile phones and tablet computers.

[0003] LCDs are not self-luminous and have poor efficiency. Even if the LCD displays white, less than 10% of the light emitted by the backlight usually passes through the panel, increasing the power consumption of portable electronic devices. In addition to the backlight, LCDs also need to be equipped with polarizers, liquid crystals, and color filters, which makes it impossible to further reduce the size of LCDs.

[0004] In contrast, organic light-emitting diodes have the advantages of self-luminescence, wide viewing angle, high contrast, low power consumption, high response rate and flexibility, and have gradually replaced liquid crystal displays to become the display of the new generation of portable electronic devices. However, organic light-emitting diodes still have problems such as burn-in, short life, color decay and PWM dimming, and major manufacturers have also begun to develop the next generation of display panels.

[0005] At present, Micro LED Display is likely to become the next generation of display panels. Like OLED, Micro LED Display is self-luminous and has the advantages of high color saturation, short response time and long service life.

[0006] At present, there are still many cost and technical bottlenecks to overcome in the commercialization of micro-LEDs. In the LED manufacturing process, the epitaxial material is mainly grown on the sapphire substrate by metal organic chemical vapor deposition (MOCVD) to form an LED epitaxial wafer. The LED epitaxial wafer is etched, and a plurality of etched grooves and a plurality of platform structures (MESA) are formed on the surface of the LED epitaxial wafer. Then the LED epitaxial wafer is cut along the etched grooves to complete the production of LED grains.

[0007] During the process of etching the LED epitaxial wafer, defects and dangling bonds are formed on the etched sidewalls of the platform structure, resulting in non-radiative recombination of the etched sidewalls of the LED, thereby affecting the brightness of the LED.

[0008] The size of traditional LEDs and platform structures is much larger than the etched sidewalls, so non-radiative recombination has little effect on the overall luminous brightness and can usually be ignored. However, the size of micro-LEDs and platform structures is very small, so non-radiative recombination occurring on the etched sidewalls will have a considerable impact on the luminous brightness of the micro-LEDs. Therefore, how to reduce the non-radiative recombination generated by the etched sidewalls of micro-LEDs has become a major issue that must be faced in the process of commercializing micro-LEDs. Summary of the invention

[0009] In order to solve the above-mentioned problems of the prior art, the present invention proposes a method for manufacturing a micro-LED that reduces non-radiative recombination, which can effectively repair defects and dangling bonds on the etched side walls of the micro-LED and the platform structure (MESA), and form a passivation layer on the micro-LED and the platform structure to reduce non-radiative recombination on the etched side walls of the micro-LED.

[0010] One object of the present invention is to provide a method for manufacturing a micro-LED that reduces non-radiative recombination, which is mainly used to process an etched LED epitaxial wafer. The LED epitaxial wafer includes a substrate, a first-type semiconductor layer, an active layer, and a second-type semiconductor layer, wherein the first-type semiconductor layer, the active layer, and the second-type semiconductor layer are arranged on the substrate in a stacked manner. A plurality of etching grooves and a plurality of platform structures are formed on the surface of the etched LED epitaxial wafer, wherein the etching sidewalls of the platform structure include the exposed first-type semiconductor layer, the active layer, and the second-type semiconductor layer. The LED epitaxial wafer can then be cut along the etching grooves to produce a plurality of micro-LEDs.

[0011] During the etching process, at least one dangling bond and / or at least one defect will be formed on the etched sidewalls of the LED epitaxial wafer, and non-radiative recombination will occur on the etched sidewalls of the micro-LED and the platform structure. The size of the micro-LED is very small, usually between 10-100um, so that the size of the micro-LED and the platform structure is similar to the etched sidewalls. Therefore, when non-radiative recombination occurs on the etched sidewalls, the luminous brightness of the micro-LED will be greatly affected. To this end, the present invention proposes a method for manufacturing a micro-LED that reduces non-radiative recombination, which mainly repairs the dangling bonds and / or defects of the etched LED epitaxial wafer, and then performs atomic layer deposition on the repaired LED epitaxial wafer to form a passivation layer on the etched sidewalls of the LED epitaxial wafer, so as to prevent the micro-LED and the etched sidewalls of the platform structure from generating non-radiative recombination, and can effectively improve the luminous brightness and conversion efficiency of the micro-LED.

[0012] One object of the present invention is to provide a method for manufacturing a micro-LED that reduces non-radiative recombination, which mainly involves performing two-stage atomic layer deposition on at least one etched LED epitaxial wafer, wherein the temperatures of the two stages of atomic layer deposition are different. Performing a first atomic layer deposition on the etched LED epitaxial wafer can repair the dangling bonds and / or defects of the etched sidewalls. Performing a second atomic layer deposition on the etched LED epitaxial wafer after the first atomic layer deposition will form a passivation layer on the etched sidewalls of the LED epitaxial wafer to prevent non-radiative recombination from occurring on the micro-LED and the etched sidewalls of the platform structure.

[0013] One purpose of the present invention is to provide a method for manufacturing a micro-LED with reduced non-radiative recombination, which mainly includes placing an etched LED epitaxial wafer into a reaction chamber, and delivering a repair gas into the reaction chamber, wherein the repair gas reacts with the dangling bonds and / or defects of the etched sidewalls, and repairs the dangling bonds and / or defects of the etched LED epitaxial wafer. Then, atomic layer deposition is performed on the repaired LED epitaxial wafer to form a passivation layer on the etched sidewalls of the platform structure.

[0014] In addition, depending on the type of repair gas, it can be determined whether to provide an AC voltage to the AC coil adjacent to the reaction chamber so that the repair gas forms a plasma, wherein the plasma-formed repair gas can improve the effect and efficiency of repairing the suspended bonds and / or defects of the light-emitting diode, and is beneficial to reducing the non-radiative recombination generated in the etching side walls of the micro-light-emitting diode and the platform structure.

[0015] In order to achieve the above-mentioned purpose, the present invention proposes a method for manufacturing a micro-LED with reduced non-radiative recombination, comprising: providing at least one etched LED epitaxial wafer, the etched LED epitaxial wafer comprising a plurality of etched grooves and a plurality of platform structures, wherein the platform structure comprises a first-type semiconductor layer, an active layer and a second-type semiconductor layer, and the active layer is located between the first-type semiconductor layer and the second-type semiconductor layer; performing a first atomic layer deposition on the etched LED epitaxial wafer in a first temperature range; and performing a second atomic layer deposition on the etched LED epitaxial wafer after the first atomic layer deposition in a second temperature range, and forming a passivation layer on the first-type semiconductor layer, the active layer and the second-type semiconductor layer on at least one etched side wall of the platform structure, wherein the first temperature range is different from the second temperature range.

[0016] The present invention provides another method for manufacturing a micro-LED with reduced non-radiative recombination, comprising: providing at least one etched LED epitaxial wafer, wherein the etched LED epitaxial wafer comprises a plurality of etched grooves and a plurality of platform structures, wherein the platform structure comprises a first-type semiconductor layer, an active layer and a second-type semiconductor layer, wherein the active layer is located between the first-type semiconductor layer and the second-type semiconductor layer; placing the etched LED epitaxial wafer in a reaction chamber, and delivering a repair gas into the reaction chamber, wherein the repair gas reacts with the etched LED epitaxial wafer; and performing an atomic layer deposition on the etched LED epitaxial wafer, and forming a passivation layer on the first-type semiconductor layer, the active layer and the second-type semiconductor layer on at least one etched side wall of the platform structure.

[0017] The present invention also provides a manufacturing machine for micro-LEDs with reduced non-radiative recombination, comprising: a transfer chamber, comprising at least one transfer device, for transferring at least one etched LED epitaxial wafer, wherein the etched LED epitaxial wafer comprises a plurality of etched grooves and a plurality of platform structures, wherein the platform structure comprises a first-type semiconductor layer, an active layer and a second-type semiconductor layer, wherein the active layer is located between the first-type semiconductor layer and the second-type semiconductor layer; at least one first atomic layer deposition chamber, connected to the transfer chamber, wherein the transfer device transfers the etched LED epitaxial wafer to the first atomic layer deposition chamber, and deposits the epitaxial wafer in the first atomic layer deposition chamber. A first atomic layer deposition is performed on the etched light-emitting diode epitaxial wafer in a first temperature range in the atomic layer deposition chamber; and at least one second atomic layer deposition chamber is connected to the transfer chamber, wherein the transfer device transfers the etched light-emitting diode epitaxial wafer after the first atomic layer deposition to the second atomic layer deposition chamber, and performs a second atomic layer deposition on the etched light-emitting diode epitaxial wafer in a second temperature range in the second atomic layer deposition chamber, so as to form a passivation layer on the first type semiconductor layer, the active layer and the second type semiconductor layer on at least one etched side wall of the platform structure, wherein the first temperature range is different from the second temperature range.

[0018] The present invention provides another manufacturing machine for micro-LEDs with reduced non-radiative recombination, comprising: a transfer chamber, comprising at least one transfer device, for transferring at least one etched LED epitaxial wafer, wherein the etched LED epitaxial wafer comprises a plurality of etched grooves and a plurality of platform structures, wherein the platform structure comprises a first-type semiconductor layer, an active layer and a second-type semiconductor layer, wherein the active layer is located between the first-type semiconductor layer and the second-type semiconductor layer; at least one reaction chamber connected to the transfer chamber, wherein the transfer device transfers the etched LED epitaxial wafer to the reaction chamber, and delivers a repair gas into the reaction chamber, so that the repair gas reacts with the etched LED epitaxial wafer; and at least one atomic layer deposition chamber connected to the transfer chamber, wherein the transfer device transfers the etched LED epitaxial wafer in the reaction chamber to the atomic layer deposition chamber, and performs an atomic layer deposition on the etched LED epitaxial wafer in the atomic layer deposition chamber, so as to form a passivation layer on the first-type semiconductor layer, the active layer and the second-type semiconductor layer on at least one etched side wall of the platform structure.

[0019] In the method for manufacturing a micro-LED with reduced non-radiative recombination, the first atomic layer deposition is used to repair at least one dangling bond or at least one defect of the etched LED epitaxial wafer, and the second atomic layer deposition is used to set a passivation layer on a top surface of the platform structure.

[0020] In the method for manufacturing a micro-light-emitting diode that reduces non-radiative recombination, the first atomic layer deposition, the second atomic layer deposition and a precursor gas used in the atomic layer deposition include organic metal compounds, organic silicon compounds, silicon chloride compounds, organic aluminum compounds, water, glycols, ozone or ethanol.

[0021] In the method for manufacturing a micro-luminescent diode for reducing non-radiative recombination, atomic layer deposition is performed in a reaction chamber.

[0022] The method for manufacturing a micro-LED with reduced non-radiative recombination includes providing an AC voltage to an AC coil adjacent to a reaction chamber, so that the repair gas in the reaction chamber becomes a plasma, wherein the plasma-formed repair gas reacts with the etched LED epitaxial wafer and repairs at least one dangling bond or at least one defect of the etched LED epitaxial wafer, and a second atomic layer is deposited on a top surface of the platform structure to set a passivation layer.

[0023] In the method for manufacturing a micro-luminescent diode that reduces non-radiative recombination, the repair gas is nitrogen, oxygen or ozone.

[0024] The beneficial effects of the present invention are that it can effectively repair defects and dangling bonds on the etched side walls of the micro-LED and the platform structure, and form a passivation layer on the micro-LED and the platform structure to reduce non-radiative recombination on the etched side walls of the micro-LED. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention is a flowchart of the steps of an embodiment of a method for manufacturing a micro-LED for reducing non-radiative recombination.

[0026] Figure 2 FIG. 4 is a cross-sectional schematic diagram of an embodiment of a light emitting diode epitaxial wafer according to the present invention.

[0027] Figure 3 FIG. 1 is a cross-sectional schematic diagram of an embodiment of an etched light emitting diode epitaxial wafer according to the present invention.

[0028] Figure 4 The cross-sectional view of an embodiment of an etched light-emitting diode epitaxial wafer with a passivation layer provided thereon according to the present invention is shown.

[0029] Figure 5 The cross-sectional view of another embodiment of the light emitting diode epitaxial wafer after etching with a passivation layer provided in the present invention is shown.

[0030] Figure 6 This is a flow chart of the steps of another embodiment of the method for manufacturing a micro-LED for reducing non-radiative recombination according to the present invention.

[0031] Figure 7 It is a schematic diagram of the structure of an embodiment of a machine for manufacturing a micro-LED for reducing non-radiative recombination according to the present invention.

[0032] Explanation of the reference numerals: 20-LED epitaxial wafer; 200-etched LED epitaxial wafer; 21-substrate; 22-etched groove; 23-first type semiconductor layer; 24-platform structure; 241-etched side wall; 243-top surface; 25-active layer; 26-contact electrode; 27-second type semiconductor layer; 29-passivation layer; 40-micro LED manufacturing machine; 41-transfer chamber; 411-transfer device; 42-carrying plate; 43-first atomic layer deposition chamber; 430-reaction chamber; 45-second atomic layer deposition chamber; 450-atomic layer deposition chamber. DETAILED DESCRIPTION

[0033] See also Figure 1 , is a flowchart of the steps of an embodiment of a method for manufacturing a micro-LED for reducing non-radiative recombination according to the present invention. Figures 2 to 5, at least one light emitting diode epitaxial wafer 20 is provided, wherein the light emitting diode epitaxial wafer 20 includes a substrate 21, a first type semiconductor layer 23, an active layer 25 and a second type semiconductor layer 27. In the process of manufacturing the light emitting diode, the first type semiconductor layer 23, the active layer 25 and the second type semiconductor layer 27 can be sequentially grown on the substrate 21 by metal organic chemical vapor deposition (MOCVD), wherein the active layer 25 is located between the first type semiconductor layer 23 and the second type semiconductor layer 27, such as Figure 2 For example, the substrate 21 is a single crystal substrate such as sapphire, silicon carbide (SiC), silicon (Si), gallium arsenide (GaAs), lithium aluminate (LiAlO2), magnesium oxide (MgO), zinc oxide (ZnO), gallium nitride (GaN), aluminum nitride (AlN), or indium nitride (InN), the first type semiconductor layer 23 is an N-type semiconductor, the active layer 25 is a plurality of quantum well layers, and the second type semiconductor layer 27 is a P-type semiconductor.

[0034] The light emitting diode epitaxial wafer 20 is etched to form a plurality of etched grooves 22 and a plurality of platform structures 24 on a surface of the light emitting diode epitaxial wafer 20, wherein the etching grooves 22 expose the first type semiconductor layer 23, and an etched light emitting diode epitaxial wafer 200 is formed, as shown in steps 11 and Figure 3 shown.

[0035] The platform structure 24 of the light emitting diode epitaxial wafer 200 after etching includes a plurality of etching sidewalls 241, wherein the etching sidewalls 241 are located at the junction of the platform structure 24 and the etching grooves 22, and the platform structure 24 has an exposed first-type semiconductor layer 23, an active layer 25, and a second-type semiconductor layer 27 on the etching sidewalls 241. For example, the etching grooves 22 may be checkerboard-shaped grooves, and the platform structure 24 is a protrusion arranged in a matrix manner, which may be a square protrusion or a circular protrusion.

[0036] The structure of the LED epitaxial wafer 20 is destroyed during the etching process, and at least one dangling bond and / or at least one defect is formed on the etched sidewall 241 of the LED epitaxial wafer 200 after etching, so that the etched sidewall 241 generates non-radiative recombination.

[0037] Since the size of the micro-LED and the platform structure 24 is very small, for example, between 10-100um, which is similar to the size of the etched sidewall 241 on the micro-LED and the platform structure 24, when the etching sidewall 241 produces non-radiative recombination, it will inevitably greatly affect the brightness of the micro-LED.

[0038] To this end, the present invention performs a first atomic layer deposition on the etched LED epitaxial wafer 200 in the first temperature range, as shown in step 13. During the first atomic layer deposition process on the etched LED epitaxial wafer 200, the precursor gas may react with the etched LED epitaxial wafer 200 and repair the dangling bonds and defects of the platform structure 24 of the etched LED epitaxial wafer 200, which can preliminarily avoid non-radiative recombination of the etched sidewall 241.

[0039] The light emitting diode epitaxial wafer 200 after the first atomic layer deposition is subjected to the second atomic layer deposition in the second temperature range, and a passivation layer 29 is formed on the first type semiconductor layer 23, the active layer 25 and the second type semiconductor layer 27 on the etched sidewall 241 of the platform structure 24, as shown in steps 15 and Figure 4 As shown. In one embodiment of the present invention, the passivation layer 29 can completely cover the etching groove 22, for example, cover the bottom and side of the etching groove 22, to prevent non-radiative recombination from occurring at the etching sidewall 241 of the platform structure 24. In one embodiment of the present invention, the precursor gas used in the first atomic layer deposition and the second atomic layer deposition includes an organic metal compound, an organic silicon compound, a silicon chloride compound, an organic aluminum compound, TMA, water, a glycol, ozone or ethanol, and the passivation layer 29 can be aluminum oxide (Al2O3).

[0040] In an embodiment of the present invention, the first temperature interval for performing the first atomic layer deposition is different from the second temperature interval for performing the second atomic layer deposition. When the first temperature interval is smaller than the second temperature interval, the time of the first atomic layer deposition can be extended, and the reaction time for repairing the suspended bonds and defects of the etching sidewall 241 can be increased. When the first temperature interval is greater than the second temperature interval, the activity of the precursor gas during the first atomic layer deposition can be increased, which is also beneficial for repairing the suspended bonds and defects of the etching sidewall 241. Specifically, the above steps 13 to 15 can be applied to batch atomic layer deposition (Batch ALD) or spatial atomic layer deposition (Spatial ALD). In addition, the time of the first atomic layer deposition may be greater than or much greater than the time of the second atomic layer deposition.

[0041] The following table shows the experimental data when only the second atomic layer deposition is performed, the first atomic layer deposition is not performed, the first temperature range is smaller than the second temperature range, and the first temperature range is larger than the second temperature range. The luminous intensity difference (%) in the following table is a comparison of the intensity of the micro-LED formed under the above process conditions and the micro-LED epitaxial wafer 200 with about 5000A of silicon dioxide (SiO2) formed on the surface. In addition, the following data is not the first and / or second atomic layer deposition immediately after the etching of the LED epitaxial wafer 20 is completed, so the following data is not absolute.

[0042]

[0043]

[0044]

[0045]

[0046] As shown in Table 1, when the first atomic layer deposition is not performed, the brightness of the micro-light-emitting diode is not effectively improved. As shown in Table 2, when the first temperature interval is 200°C and the second temperature interval is 220°C, the brightness of the micro-light-emitting diode is slightly improved. As shown in Table 3, when the first temperature interval is 270°C and the second temperature interval is 220°C, the brightness of the micro-light-emitting diode is significantly improved. As shown in Table 4, when the first temperature interval is 150°C and the second temperature interval is 220°C, the brightness of the micro-light-emitting diode is also significantly improved. It can be explained that when the first temperature interval of the first atomic layer deposition is different from the second temperature interval of the second atomic layer deposition, the luminous brightness of the micro-light-emitting diode can be improved. Of course, the data in the above table is only the experimental data of the present invention, and is not a limitation of the scope of rights of the present invention.

[0047] In another embodiment of the present invention, the second atomic layer deposition may also be used to form a passivation layer 29 on a top surface 243 of the platform structure 24, wherein the passivation layer 29 not only covers the etching sidewalls 241 of the platform structure 24, but also extends to the top surface 243 of the platform structure 24. Figure 5 In addition, the passivation layer 29 is disposed on the etched sidewalls 241 and the top surface 243 of the platform structure 24 , and the passivation layer 29 can also be used as a reflective layer to reflect the light generated by the micro-LED and the platform structure 24 .

[0048] In practical applications, the contact electrode 26 may be disposed on the platform structure 24 first, and then the passivation layer 29 may be disposed, wherein the passivation layer 29 may be in contact with the contact electrode 26, or the contact electrode 26 may be disposed on the platform structure 24 after the passivation layer 29 is disposed. After the passivation layer 29 is disposed, the etched LED epitaxial wafer 200 may be cut along the etching grooves 22 to form a plurality of micro LEDs.

[0049] In one embodiment of the present invention, contact electrodes 26, a reflective layer, a transparent current diffusion layer, etc. can be disposed on the etched LED epitaxial wafer 200. These structures are common in the field of LED technology. The above structures are not the focus of the present invention and will not be described in detail.

[0050] See also Figure 6 , which is a flowchart of another embodiment of the method for manufacturing a micro-LED for reducing non-radiative recombination according to the present invention. Figures 2 to 5First, at least one light emitting diode epitaxial wafer 20 is provided, wherein the light emitting diode epitaxial wafer 20 includes a substrate 21 , a first type semiconductor layer 23 , an active layer 25 and a second type semiconductor layer 27 .

[0051] The light emitting diode epitaxial wafer 20 is etched to form a plurality of etched grooves 22 and a plurality of platform structures 24 on the light emitting diode epitaxial wafer 20, and an etched light emitting diode epitaxial wafer 200 is formed, as shown in step 11 and Figure 3 The platform structure 24 of the light emitting diode epitaxial wafer 200 after etching includes a plurality of etching sidewalls 241, wherein the etching sidewalls 241 are located at the junction of the platform structure 24 and the etching groove 22, and the etching sidewalls 241 have the exposed first-type semiconductor layer 23, active layer 25 and second-type semiconductor layer 27. For example, the etching groove 22 can be a checkerboard-shaped groove, and the platform structure 24 is a protrusion arranged in a matrix manner, which can be a square protrusion or a circular protrusion.

[0052] The etched light emitting diode epitaxial wafer 200 is placed in a reaction chamber, and a repair gas is delivered into the reaction chamber, as shown in step 33. In practical applications, the repair gas can be selected according to the materials of the first semiconductor layer 23, the active layer 25 and the second semiconductor layer 27, wherein the repair gas includes oxygen, nitrogen or ozone.

[0053] An AC voltage is provided to an AC coil adjacent to the reaction chamber, so that the repair gas in the reaction chamber becomes plasma, wherein the plasma-formed repair gas reacts with the etched light-emitting diode epitaxial wafer 200 and repairs the etched light-emitting diode epitaxial wafer 200, as shown in step 35. For example, when the first-type semiconductor layer 23, the active layer 25 and the second-type semiconductor layer 27 are indium gallium nitride (InGaN), the repair gas can be nitrogen, and the plasma-formed repair gas can be used to repair the suspended bonds and defects of the etched side 241 of the platform structure 24. In one embodiment of the present invention, the reaction chamber can be a general physical vapor deposition chamber or an atomic layer deposition chamber, so that the plasma-formed repair gas can be used to repair the etched light-emitting diode epitaxial wafer 200.

[0054] In addition, when the repair gas is ozone, there is no need to provide AC voltage to the AC coil. As long as a certain concentration of ozone is provided in the reaction chamber, the ozone can react with the etched light-emitting diode epitaxial wafer 200 and repair the suspended bonds and defects of the etched side 241 of the platform structure 24. Therefore, step 35 is not a necessary step of the present invention, and whether to perform step 35 can be determined based on the type of repair gas. In addition, after the repair gas is transmitted to the reaction chamber, the temperature of the reaction chamber and the repair gas can be increased.

[0055] Atomic layer deposition is performed on the repaired etched light-emitting diode epitaxial wafer 200, and a passivation layer 29 is formed on at least one etched side 241 of the platform structure 24, wherein the passivation layer 29 covers the first-type semiconductor layer 23, the active layer 25, and the second-type semiconductor layer 27 on the etched side 241 of the platform structure 24, as shown in step 37. In one embodiment of the present invention, the precursor gas used in the atomic layer deposition includes an organic metal compound, an organic silicon compound, a chlorinated silicon compound, an organic aluminum compound, TMA, water, a glycol, ozone, or ethanol, and the passivation layer 29 can be aluminum oxide (Al2O3).

[0056] The repair reaction and atomic layer deposition process described in steps 33 to 37 can be performed in the same or two different reaction chambers. For example, when the temperatures of the repair reaction and the atomic layer deposition process are the same or similar, the repair reaction and the atomic layer deposition process can be performed in the same reaction chamber or the same atomic layer deposition chamber. Specifically, steps 33 to 37 can be applied to batch atomic layer deposition (Batch ALD) or spatial atomic layer deposition (Spatial ALD). In addition, the time of the repair reaction can be greater than or much greater than the time of the atomic layer deposition.

[0057] See also Figure 7 , is a schematic diagram of the structure of an embodiment of a manufacturing machine for reducing non-radiative recombination of micro-LEDs according to the present invention. Figure 1 The micro-LED manufacturing machine 40 includes a transfer chamber 41, at least one first atomic layer deposition chamber 43 and at least one second atomic layer deposition chamber 45, wherein the transfer chamber 41 connects the first atomic layer deposition chamber 43 and the second atomic layer deposition chamber 45, and the transfer chamber 41, the first atomic layer deposition chamber 43 and the second atomic layer deposition chamber 45 maintain low pressure or vacuum.

[0058] In one embodiment of the present invention, the transfer chamber 41 includes at least one transfer device 411, for example, the transfer device 411 can be a robot arm, wherein the transfer device 411 is used to carry and transfer at least one etched LED epitaxial wafer 200. In practical applications, a plurality of etched LED epitaxial wafers 200 can be placed on a carrier plate 42, and the carrier plate 42 and the etched LED epitaxial wafers 200 can be carried and transferred by the transfer device 411. The transfer device 411 can be retracted relative to the first atomic layer deposition chamber 43 and the second atomic layer deposition chamber 45, and transfer the etched LED epitaxial wafer 200 to the first atomic layer deposition chamber 43 and the second atomic layer deposition chamber 45, or take the etched LED epitaxial wafer 200 out of the first atomic layer deposition chamber 43 and the second atomic layer deposition chamber 45.

[0059] The conveyor 411 first transports the etched LED epitaxial wafer 200 to the first atomic layer deposition chamber 43, and performs the first atomic layer deposition on the etched LED epitaxial wafer 200 at a first temperature range in the first atomic layer deposition chamber 43. When the first atomic layer deposition is performed in the first atomic layer deposition chamber 43, the precursor gas can be used to repair the dangling bonds and defects on the etched sidewalls 241 of the platform structure 24, and initially prevent the etched sidewalls 241 from non-radiative recombination.

[0060] Then, the conveying device 411 takes out the etched light-emitting diode epitaxial wafer 200 after the first atomic layer deposition from the first atomic layer deposition chamber 43 and conveys it to the second atomic layer deposition chamber 45. The second atomic layer deposition chamber 45 performs the second atomic layer deposition on the etched light-emitting diode epitaxial wafer 200 at a second temperature range to form a passivation layer 29 on the etched sidewall 241 of the etched light-emitting diode epitaxial wafer 200, wherein the passivation layer 29 covers the first type semiconductor layer 23, the active layer 25 and the second type semiconductor layer 27 on the etched sidewall 241 of the platform structure 24 to prevent non-radiative recombination from occurring on the etched sidewall 241 of the platform structure 24.

[0061] In the embodiment of the present invention, the first temperature interval is different from the second temperature interval. When the first temperature interval is smaller than the second temperature interval, the time of the first atomic layer deposition can be extended, and the time of repairing the suspended bonds and defects on the etching sidewall 241 can be increased. When the first temperature interval is larger than the second temperature interval, the activity of the precursor gas during the first atomic layer deposition can be increased, which is also beneficial to repairing the suspended bonds and defects on the etching sidewall 241.

[0062] In another embodiment of the present invention, the first atomic layer deposition chamber 43 may be a reaction chamber 430, and the second atomic layer deposition chamber 45 may be an atomic layer deposition chamber 450. The reaction chamber 430 and the atomic layer deposition chamber 450 are connected to the transfer chamber 41, and the etched light-emitting diode epitaxial wafer 200 is transferred between the reaction chamber 430 and the atomic layer deposition chamber 450 through the transfer device 411 of the transfer chamber 41.

[0063] The conveying device 411 first transports the etched LED epitaxial wafer 200 to the reaction chamber 43, and transports a repair gas into the reaction chamber 430. In one embodiment of the present invention, the micro-LED manufacturing machine 40 may include an AC coil, wherein the AC coil is adjacent to the reaction chamber 43 and is used to form a magnetic field in the reaction chamber 430, so that the repair gas in the reaction chamber 430 becomes plasma. The plasma-formed repair gas will react with the etched LED epitaxial wafer 200 and repair the etched LED epitaxial wafer 200, for example, repair the suspended bonds and defects of the first-type semiconductor layer 23, the active layer 25 and the second-type semiconductor layer 27 on the etched sidewall 241 of the platform structure 24. In actual application, the repair gas can be selected according to the materials of the first-type semiconductor layer 23, the active layer 25 and the second-type semiconductor layer 27, wherein the repair gas includes oxygen, nitrogen and ozone.

[0064] In addition, when the repair gas is ozone, there is no need to provide an AC voltage to the AC coil. As long as a certain concentration of ozone is provided in the reaction chamber, the ozone can react with the etched light-emitting diode epitaxial wafer 200.

[0065] The conveying device 411 takes out the repaired etched light-emitting diode epitaxial wafer 200 in the reaction chamber 430 and conveys it to the atomic layer deposition chamber 450. The atomic layer deposition chamber 450 performs an atomic layer deposition on the etched light-emitting diode epitaxial wafer 200 to form a passivation layer 29 on the etched sidewall 241 of the platform structure 24, for example, the passivation layer 29 covers the first type semiconductor layer 23, the active layer 25 and the second type semiconductor layer 27 on the etched sidewall 241 to prevent non-radiative recombination from occurring on the etched sidewall 241 of the platform structure 24.

[0066] Advantages of the present invention:

[0067] It can effectively repair the defects and dangling bonds on the etched side walls of the micro-LED and platform structures, and form a passivation layer on the micro-LED and platform structures to reduce the non-radiative recombination on the etched side walls of the micro-LED.

[0068] The above is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. That is, all equivalent changes and modifications to the shape, structure, characteristics and spirit described in the patent application scope of the present invention should be included in the patent application scope of the present invention.

Claims

1. A method for manufacturing a micro-light-emitting diode for reducing non-radiative recombination, characterized in that: include: Providing at least one etched light-emitting diode epitaxial wafer, the etched light-emitting diode epitaxial wafer comprising a plurality of etched grooves and a plurality of platform structures, wherein the platform structure comprises a first-type semiconductor layer, an active layer and a second-type semiconductor layer, and the active layer is located between the first-type semiconductor layer and the second-type semiconductor layer; The etched light emitting diode epitaxial wafer is subjected to a first atomic layer deposition in a first temperature range; and The etched light emitting diode epitaxial wafer after the first atomic layer deposition is subjected to a second atomic layer deposition in a second temperature range, and a passivation layer is formed on the first-type semiconductor layer, the active layer and the second-type semiconductor layer on at least one etched side wall of the platform structure, wherein the first temperature range is greater than the second temperature range, and the time of the first atomic layer deposition is greater than or much greater than the time of the second atomic layer deposition; The first atomic layer deposition is used to repair at least one dangling bond or at least one defect of the etched light emitting diode epitaxial wafer; The passivation layer completely covers a plurality of the etching grooves.

2. The method for manufacturing a micro-LED for reducing non-radiative recombination according to claim 1, characterized in that: The second atomic layer is deposited on a top surface of the platform structure to set the passivation layer.

3. The method for manufacturing a micro-LED with reduced non-radiative recombination according to claim 1, characterized in that: A precursor gas used in the first atomic layer deposition and the second atomic layer deposition includes an organic metal compound, an organic silicon compound, a chlorinated silicon compound, water, a glycol, ozone or ethanol.

4. A method for manufacturing a micro-light-emitting diode for reducing non-radiative recombination, characterized in that: include: Providing at least one etched light-emitting diode epitaxial wafer, the etched light-emitting diode epitaxial wafer comprising a plurality of etched grooves and a plurality of platform structures, wherein the platform structure comprises a first-type semiconductor layer, an active layer and a second-type semiconductor layer, and the active layer is located between the first-type semiconductor layer and the second-type semiconductor layer; Placing the etched light-emitting diode epitaxial wafer into a reaction chamber, and delivering a repair gas into the reaction chamber to perform a repair reaction, wherein the repair gas reacts with the etched light-emitting diode epitaxial wafer, and the repair gas repairs at least one dangling bond or at least one defect of the etched light-emitting diode epitaxial wafer; and An atomic layer deposition is performed on the etched light-emitting diode epitaxial wafer, and a passivation layer is formed on the first-type semiconductor layer, the active layer and the second-type semiconductor layer on at least one etched side wall of the platform structure, wherein the passivation layer completely covers a plurality of the etched grooves, and the repair reaction time is greater than or much greater than the atomic layer deposition time.

5. The method for manufacturing a micro-LED with reduced non-radiative recombination according to claim 4, characterized in that: The atomic layer deposition is carried out in the reaction chamber.

6. The method for manufacturing a micro-LED with reduced non-radiative recombination according to claim 4, characterized in that: The invention comprises providing an AC voltage to an AC coil adjacent to the reaction chamber, so that the repair gas in the reaction chamber becomes a plasma, wherein the plasma-formed repair gas reacts with the etched light-emitting diode epitaxial wafer, and the second atomic layer is deposited on a top surface of the platform structure to set the passivation layer.

7. The method for manufacturing a micro-LED with reduced non-radiative recombination according to claim 4, characterized in that: A precursor gas used in the atomic layer deposition process includes an organic metal compound, an organic silicon compound, a chlorinated silicon compound, water, a glycol, ozone or ethanol.

8. The method for manufacturing a micro-LED with reduced non-radiative recombination according to claim 4, characterized in that: The repair gas is nitrogen, oxygen or ozone.

9. A machine for manufacturing a micro-LED for reducing non-radiative recombination, characterized in that: include: A transfer chamber, comprising at least one transfer device, for transferring at least one etched light-emitting diode epitaxial wafer, wherein the etched light-emitting diode epitaxial wafer comprises a plurality of etched grooves and a plurality of platform structures, wherein the platform structure comprises a first-type semiconductor layer, an active layer and a second-type semiconductor layer, wherein the active layer is located between the first-type semiconductor layer and the second-type semiconductor layer; At least one first atomic layer deposition chamber connected to the transfer chamber, wherein the transfer device transfers the etched light-emitting diode epitaxial wafer to the first atomic layer deposition chamber, and performs a first atomic layer deposition on the etched light-emitting diode epitaxial wafer at a first temperature interval in the first atomic layer deposition chamber, wherein the first atomic layer deposition is used to repair at least one dangling bond or at least one defect of the etched light-emitting diode epitaxial wafer; and At least one second atomic layer deposition chamber is connected to the transfer chamber, wherein the transfer device transfers the etched light-emitting diode epitaxial wafer after the first atomic layer deposition to the second atomic layer deposition chamber, and performs a second atomic layer deposition on the etched light-emitting diode epitaxial wafer at a second temperature range in the second atomic layer deposition chamber to form a passivation layer on the first-type semiconductor layer, the active layer and the second-type semiconductor layer on at least one etched side wall of the platform structure, wherein the passivation layer completely covers a plurality of the etched grooves, wherein the first temperature range is greater than the second temperature range, and the time of the first atomic layer deposition is greater than or much greater than the time of the second atomic layer deposition.

10. A machine for manufacturing a micro-LED for reducing non-radiative recombination, characterized in that: include: A transfer chamber, comprising at least one transfer device, for transferring at least one etched light-emitting diode epitaxial wafer, wherein the etched light-emitting diode epitaxial wafer comprises a plurality of etched grooves and a plurality of platform structures, wherein the platform structure comprises a first-type semiconductor layer, an active layer and a second-type semiconductor layer, wherein the active layer is located between the first-type semiconductor layer and the second-type semiconductor layer; At least one reaction chamber connected to the transfer chamber, wherein the transfer device transfers the etched LED epitaxial wafer to the reaction chamber, and delivers a repair gas into the reaction chamber, so that the repair gas and the etched LED epitaxial wafer undergo a repair reaction, and the repair gas repairs at least one dangling bond or at least one defect of the etched LED epitaxial wafer; and At least one atomic layer deposition chamber is connected to the transfer chamber, wherein the transfer device transfers the etched light-emitting diode epitaxial wafer in the reaction chamber to the atomic layer deposition chamber, and performs an atomic layer deposition on the etched light-emitting diode epitaxial wafer in the atomic layer deposition chamber to form a passivation layer on the first-type semiconductor layer, the active layer and the second-type semiconductor layer on at least one etched side wall of the platform structure, wherein the passivation layer completely covers a plurality of the etched grooves, and the repair reaction time is greater than or much greater than the atomic layer deposition time.

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