Micro-led panel with regrowth layer and method of manufacturing the same

Abstract

A micro LED panel having a micro LED array and a system and method of manufacturing the micro LED panel are provided according to the present disclosure. The micro LED array includes at least one micro LED structure. The micro LED structure includes at least: a mesa structure and a regrowth layer. In some embodiments, the mesa structure includes a first type of epitaxial layer, a light emitting layer, and a second type of epitaxial layer. In some embodiments, the regrowth layer is grown on at least a portion of sidewalls of the first type of epitaxial layer, an entire sidewall of the light emitting layer, and at least a portion of sidewalls of the second type of epitaxial layer. The present disclosure can reduce non-radiative recombination at the sidewalls of the mesa structure and improve the light emitting efficiency of the micro LED structure.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to light emitting diode (LED) technology, and more particularly to a micro-LED panel and a method of manufacturing the micro-LED structure. BACKGROUND

[0002] Display technology is becoming increasingly important in today's commercial electronic devices. These display panels are widely used in fixed large screens, such as liquid crystal televisions (LCD TVs) and organic light emitting diode televisions (OLED TVs), as well as portable electronic devices, such as laptop personal computers, smartphones, tablets, and wearable electronic devices.

[0003] Inorganic micro light emitting diodes are increasingly important due to their use in various applications including self-emitting micro displays, visible light communication, and optogenetics. Micro-LEDs show higher output performance than conventional LEDs due to better strain relaxation, improved light extraction efficiency, and uniform current spreading. Micro-LEDs also exhibit improved thermal effects compared to conventional LEDs and operate at higher current densities, fast response rates, greater operating temperature ranges, higher resolutions, color gamut, contrast, and lower power consumption.

[0004] In order to achieve higher pixel density, the size of micro-LEDs is reduced to less than 200 nm. However, the efficiency and carrier lifetime of devices based on micro-LED arrays are drastically reduced with the reduction in micro-LED size due to poor p-type conduction and surface recombination caused by top-down etching. The performance of micro-LEDs is also severely affected by the quantum confined Stark effect, particularly the polarization field due to strain, which results in unstable operation and a significant change in emission wavelength with increasing current. In addition, as the micro-LED diameter decreases, a large number of surface states and defects are formed at the surface of the micro-LED structure by inductively coupled plasma (ICP) etching, which increases non-radiative recombination at the surface of the micro-LED structure.

[0005] In addition, the emission of conventional micro-LED structures is mainly distributed in any direction that exhibits poor directional emission and reduces the light intensity along the vertical direction. In order to achieve directional emission of micro-LED structures, additional reflective structures are configured around the mesa and at the bottom of the mesa of the micro-LED structure to reflect the emitted light to the same direction, which results in a complex manufacturing process and increases the cost of micro-LEDs.

[0006] Furthermore, in devices based on micro-LED arrays, one micro-LED is typically used as one pixel, such as in monolithic micro-LED array panels. However, micro-LED structures with smaller diameters exhibit lower external quantum efficiency (EQE), which reduces the light efficiency of each pixel.

[0007] The above description is merely intended to help understand the technical solutions of the present application and does not constitute an acknowledgement to the above as the prior art. SUMMARY

[0008] There is a need for improved display designs that improve upon and help address the shortcomings of conventional display systems such as those described above. In particular, there is a need for display panels with improved efficiency and better images.

[0009] To overcome the above-mentioned shortcomings, the present application provides a micro-LED panel to improve light-emitting efficiency, avoid crosstalk, minimize surface carrier loss, and optimize quantum well sidewall area.

[0010] To achieve the above-mentioned object, some exemplary embodiments of the present disclosure provide a micro-LED panel with an array of micro-LED structures, comprising: at least one micro-LED structure, wherein the micro-LED structure comprises at least:

[0011] a mesa structure, wherein the mesa structure comprises, from bottom to top: a first type of epitaxial layer, a light-emitting layer, and a second type of epitaxial layer; and

[0012] a regrowth layer, wherein the regrowth layer is grown on at least part of the sidewall of the first type of epitaxial layer, the entire sidewall of the light-emitting layer, and part of the sidewall of the second type of epitaxial layer.

[0013] In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, a dielectric layer is formed between adjacent mesa structures; and the top end of the regrowth layer further protrudes into the dielectric layer.

[0014] In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the regrowth layer protruding into the dielectric layer is connected to the adjacent light-emitting layer and the adjacent first type of epitaxial layer.

[0015] In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the regrowth layer is grown on the entire sidewall of the first type of epitaxial layer, the entire sidewall of the light-emitting layer, and part of the first type of epitaxial layer.

[0016] In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the regrowth layer is grown on part of the sidewall of the first type of epitaxial layer, the entire sidewall of the light-emitting layer, and part of the sidewall of the second type of epitaxial layer.

[0017] In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the regrowth layer on the sidewall of the light-emitting layer is not parallel to the extension direction of the light-emitting layer.

[0018] In some example embodiments of the micro LED panel, or any combination of the example embodiments, the regrowth layer on the sidewall of the light emitting layer has a tilt angle of 30 degrees to 90 degrees with respect to the extension direction of the light emitting layer; and the regrowth layer protruding into the dielectric layer is parallel to the bottom surface of the second type of epitaxial layer.

[0019] In some example embodiments of the micro LED panel, or any combination of the example embodiments, the mesa structure has a diameter of no more than 3 pm.

[0020] In some example embodiments of the micro LED panel, or any combination of the example embodiments, the light emitting layer includes a top surface, an edge surface, and a bottom surface; and the regrowth layer is grown on the edge surface of the light emitting layer, but not on the top surface and the bottom surface of the light emitting layer.

[0021] In some example embodiments of the micro LED panel, or any combination of the example embodiments, the light emitting layer includes a plurality of pairs of quantum wells; and the regrowth layer on the sidewall of the light emitting layer is not parallel to the surface of each pair of the plurality of pairs of quantum wells.

[0022] In some example embodiments of the micro LED panel, or any combination of the example embodiments, the light emitting layer has a straight line shape without any bending.

[0023] In some example embodiments of the micro LED panel, or any combination of the example embodiments, the material of the regrowth layer with intrinsic doping ions is the same as the material of the first type of epitaxial layer and / or the material of the second type of epitaxial layer, but without intentional doping ions.

[0024] In some example embodiments of the micro LED panel, or any combination of the example embodiments, the material of the regrowth layer is one or more of GaP, AlP, GaAs, InP, AlInP, GaInP, AlN, GaN, and / or InN.

[0025] In some example embodiments of the micro LED panel, or any combination of the example embodiments, the material of the regrowth layer is single-crystalline, the material of the first type of epitaxial layer is single-crystalline, and the material of the second type of epitaxial layer is single-crystalline.

[0026] In some example embodiments of the micro LED panel, or any combination of the example embodiments, the regrowth layer has a band gap greater than the band gap of the light emitting layer.

[0027] In some example embodiments of the micro LED panel, or any combination of the example embodiments, the regrowth layer has a thickness less than the thickness of the light emitting layer.

[0028] In some example embodiments or any combination of example embodiments of the micro LED panel, the thickness of the regrowth layer is not greater than 100 nm.

[0029] In some example embodiments or any combination of example embodiments of the micro LED panel, the resistance of the regrowth layer is higher than the resistance of the light emitting layer.

[0030] In some example embodiments or any combination of example embodiments of the micro LED panel, the regrowth layer is electrically non-conductive.

[0031] In some example embodiments or any combination of example embodiments of the micro LED panel, a dielectric layer is formed on the surface of the regrowth layer between adjacent mesa structures.

[0032] In some example embodiments or any combination of example embodiments of the micro LED panel, the material of the dielectric layer is one or more of SiO2, SiNx, Al2O3, AlN, HfO2, TiO2, and / or ZrO2.

[0033] In some example embodiments or any combination of example embodiments of the micro LED panel, the material of the first type of epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and / or AlGaInP, and the material of the second type of epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and / or AlGaInP.

[0034] Some example embodiments of the present disclosure provide a method of manufacturing a micro LED panel, the method comprising:

[0035] Step 1, providing a semiconductor substrate having an epitaxial structure, wherein the epitaxial structure comprises, from top to bottom, a first type of epitaxial layer, a light emitting layer, and a second type of epitaxial layer;

[0036] Step 2, forming mesa structures by patterning the epitaxial structure;

[0037] Step 3, forming a first mask pattern on the semiconductor substrate to cover sidewalls of the first type of epitaxial layer, sidewalls of the light emitting layer, and part of the sidewalls of the second type of epitaxial layer;

[0038] Step 4, depositing a first dielectric layer on the substrate between adjacent mesa structures, the top of the first dielectric layer being lower than the bottom of the light emitting layer;

[0039] Step 5, removing the first mask pattern;

[0040] Step 6, forming a regrowth layer on the entire sidewall of the light emitting layer, on the partial sidewall of the second type epitaxial layer, and on at least partial sidewall of the first type epitaxial layer by an epitaxial material regrowth process;

[0041] Step 7, forming a bottom contact in the regrowth layer on the top surface of the first type epitaxial layer, and forming a second dielectric layer on the regrowth layer, the second dielectric layer having an opening exposing a top of the bottom contact;

[0042] Step 8, forming a bottom connection structure in the opening;

[0043] Step 9, bonding the first type epitaxial layer and the bottom connection structure with an IC backplane by inverting the semiconductor substrate; then, removing the semiconductor substrate; and

[0044] Step 10, forming a top contact and a top conductive layer on the second type epitaxial layer.

[0045] In some example embodiments or any combination of the example embodiments, the method of manufacturing the micro LED panel further comprises: in Step 6, before forming the regrowth layer, forming a second mask pattern covering the top and partial sidewall of the first type epitaxial layer, wherein the regrowth layer is formed on the entire sidewall of the light emitting layer, on at least partial sidewall of the first type epitaxial layer, and on the partial sidewall of the second type epitaxial layer, and after forming the regrowth layer, removing the second mask pattern.

[0046] In some example embodiments or any combination of the example embodiments of the method of manufacturing the micro LED panel, in Step 6, the regrowth layer is directly formed on the entire sidewall of the light emitting layer, on the entire sidewall of the first type epitaxial layer, and on the top of the first type epitaxial layer.

[0047] In some example embodiments or any combination of the example embodiments of the method of manufacturing the micro LED panel, in Step 6, the temperature in the regrowth process is 400-1000 °C, and the regrowth time is 5-1000 seconds.

[0048] Some example embodiments of the present disclosure provide a micro LED panel having an array of micro LED structures, comprising:

[0049] at least one micro LED structure, wherein the micro LED structure comprises:

[0050] a mesa structure, wherein the mesa structure comprises, from bottom to top: a first type epitaxial layer, a light emitting layer, and a second type epitaxial layer; and

[0051] a regrowth layer, wherein the regrowth layer is grown on partial sidewall of the first type epitaxial layer, on the entire sidewall of the second type epitaxial layer, and on the entire sidewall of the light emitting layer.

[0052] In some example embodiments or any combination of the example embodiments of the micro LED panel, a dielectric layer is formed between adjacent micro LED structures; and the top end of the regrowth layer further protrudes along a top surface of the dielectric layer.

[0053] In some example embodiments or any combination of the example embodiments of the micro LED panel, the regrowth layer on the sidewall of the light emitting layer is not parallel to the extension direction of the light emitting layer.

[0054] In some example embodiments or any combination of the example embodiments of the micro LED panel, the regrowth layer on the sidewall of the light emitting layer has an inclination angle of 30 degrees to 90 degrees with respect to the extension direction of the light emitting layer; and the regrowth layer protruding along the top of the dielectric layer is parallel to the top surface of the dielectric layer.

[0055] In some example embodiments or any combination of the example embodiments of the micro LED panel, the regrowth layer protruding along the top of the dielectric layer is connected to the adjacent light emitting layer and the second type epitaxial layer.

[0056] In some example embodiments or any combination of the example embodiments of the micro LED panel, the diameter of the mesa structure is no more than 3 pm.

[0057] In some example embodiments or any combination of the example embodiments of the micro LED panel, the light emitting layer includes a top surface, an edge surface, and a bottom surface; and the regrowth layer is grown on the edge surface of the light emitting layer, but not on the top surface and the bottom surface of the light emitting layer.

[0058] In some example embodiments or any combination of the example embodiments of the micro LED panel, the light emitting layer includes a plurality of pairs of quantum wells; and the regrowth layer on the sidewall of the light emitting layer is not parallel to each pair of the plurality of pairs of quantum wells.

[0059] In some example embodiments or any combination of the example embodiments of the micro LED panel, the light emitting layer has a straight line shape without any bending.

[0060] In some example embodiments or any combination of the example embodiments of the micro LED panel, the material of the regrowth layer with intrinsic doping ions is the same as the material of the first type epitaxial layer and / or the material of the second type epitaxial layer, but without intentional doping ions.

[0061] In some example embodiments or any combination of the example embodiments of the micro LED panel, the material of the regrowth layer is one or more of GaP, AlP, GaAs, InP, AlInP, GaInP, AlN, GaN, and / or InN.

[0062] In some example embodiments or any combination of example embodiments of the micro LED panel, the material of the regrowth layer is single crystalline, the material of the first type of epitaxial layer is single crystalline, and the material of the second type of epitaxial layer is single crystalline.

[0063] In some example embodiments or any combination of example embodiments of the micro LED panel, the bandgap of the regrowth layer is greater than the bandgap of the light emitting layer.

[0064] In some example embodiments or any combination of example embodiments of the micro LED panel, the thickness of the regrowth layer is less than the thickness of the light emitting layer.

[0065] In some example embodiments or any combination of example embodiments of the micro LED panel, the thickness of the regrowth layer is not greater than 100 nm.

[0066] In some example embodiments or any combination of example embodiments of the micro LED panel, the electrical resistance of the regrowth layer is higher than the electrical resistance of the light emitting layer.

[0067] In some example embodiments or any combination of example embodiments of the micro LED panel, the regrowth layer is electrically non-conductive.

[0068] In some example embodiments or any combination of example embodiments of the micro LED panel, a dielectric layer is further formed on the surface of the regrowth layer.

[0069] In some example embodiments or any combination of example embodiments of the micro LED panel, the material of the dielectric layer is one or more of SiO2, SiNx, Al2O3, AlN, HfO2, TiO2, and / or ZrO2.

[0070] In some example embodiments or any combination of example embodiments of the micro LED panel, the material of the first type of epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and / or AlGaInP, and the material of the second type of epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and / or AlGaInP.

[0071] Some example embodiments of the present disclosure provide a method of manufacturing a micro LED panel, the method comprising:

[0072] Step 1, providing a semiconductor substrate having an epitaxial structure outside, wherein the epitaxial structure comprises a first type of epitaxial layer, a light emitting layer, and a second type of epitaxial layer from top to bottom;

[0073] Step 2, forming a mesa structure by patterning the epitaxial structure;

[0074] Step 3: Form a mask pattern on the semiconductor substrate to cover the top and part of the sidewalls of the first type of epitaxial layer;

[0075] Step 4: A regenerated layer is formed on the entire sidewall of the light-emitting layer, the entire sidewall of the second type epitaxial layer, and part of the sidewall of the first type epitaxial layer using an epitaxial material regeneration process.

[0076] Step 5: Remove the mask pattern;

[0077] Step 6: A bottom contact is formed on the surface of the first type epitaxial layer, and a dielectric layer is formed on the regenerated layer and on the top and sidewalls of the first type epitaxial layer, the dielectric layer having an opening at the top that exposes the bottom contact;

[0078] Step 7: Form the bottom connection structure in the opening;

[0079] Step 8: By inverting the semiconductor substrate, the first type of epitaxial layer and the bottom interconnect structure are bonded to the IC backplane; then, the semiconductor substrate is removed; and

[0080] Step 9: Form a top contact and a top conductive layer on the second type of epitaxial layer.

[0081] In some exemplary embodiments or any combination of exemplary embodiments of the method for manufacturing a micro LED panel, in step 4, a regenerated layer is further formed on a substrate between adjacent mesa structures; the temperature in the regenerated process is 400°C to 1000°C, and the regeneration time is 5 seconds to 1000 seconds.

[0082] Some exemplary embodiments of this disclosure provide a microLED panel including a microLED structure array, comprising:

[0083] At least one microLED structure, wherein the microLED structure comprises:

[0084] The mesa structure, from bottom to top, includes: a first type epitaxial layer, a light-emitting layer, and a second type epitaxial layer; and

[0085] The regenerated layer grows on the entire sidewall of the first type epitaxial layer, the entire sidewall of the light-emitting layer, and the entire sidewall of the second type epitaxial layer.

[0086] In some exemplary embodiments or any combination of exemplary embodiments of the micro LED panel, a dielectric layer is formed between adjacent mesa structures.

[0087] In some exemplary embodiments or any combination of exemplary embodiments of the micro LED panel, the top of the regenerated layer further protrudes along the top surface of the dielectric layer.

[0088] In some example embodiments or any combination of the example embodiments of the micro LED panel, the regrowth layer on the sidewall of the light emitting layer is not parallel to the extension direction of the light emitting layer.

[0089] In some example embodiments or any combination of the example embodiments of the micro LED panel, the regrowth layer on the sidewall of the light emitting layer has an inclination angle of 30 degrees to 90 degrees with respect to the extension direction of the light emitting layer; and the regrowth layer protruding along the top of the dielectric layer is parallel to the top surface of the dielectric layer.

[0090] In some example embodiments or any combination of the example embodiments of the micro LED panel, the regrowth layer protruding along the top of the dielectric layer is connected to the adjacent second type epitaxial layer.

[0091] In some example embodiments or any combination of the example embodiments of the micro LED panel, the regrowth layer is further formed on the entire sidewall of the mesa structure.

[0092] In some example embodiments or any combination of the example embodiments of the micro LED panel, the regrowth layer is further formed on the bottom surface of the first type epitaxial layer.

[0093] In some example embodiments or any combination of the example embodiments of the micro LED panel, the diameter of the mesa structure is no more than 3 pm.

[0094] In some example embodiments or any combination of the example embodiments of the micro LED panel, the light emitting layer includes a top surface, an edge surface, and a bottom surface; and the regrowth layer is grown on the edge surface of the light emitting layer, but not on the top surface and the bottom surface of the light emitting layer.

[0095] In some example embodiments or any combination of the example embodiments of the micro LED panel, the light emitting layer includes a plurality of pairs of quantum wells; and the regrowth layer on the sidewall of the light emitting layer is not parallel to the surface of each pair of the plurality of pairs of quantum wells.

[0096] In some example embodiments or any combination of the example embodiments of the micro LED panel, the light emitting layer has a straight line shape without any bending.

[0097] In some example embodiments or any combination of the example embodiments of the micro LED panel, the material of the regrowth layer with intrinsic doping ions is the same as the material of the first type epitaxial layer and / or the material of the second type epitaxial layer, but without intentional doping ions.

[0098] In some example embodiments or any combination of example embodiments of the micro LED panel, the material of the regrowth layer is one or more of GaP, AlP, GaAs, InP, AlInP, GaInP, AIN, GaN, and / or InN.

[0099] In some example embodiments or any combination of example embodiments of the micro LED panel, the material of the regrowth layer is single crystalline, the material of the first type of epitaxial layer is single crystalline, and the material of the second type of epitaxial layer is single crystalline.

[0100] In some example embodiments or any combination of example embodiments of the micro LED panel, the bandgap of the regrowth layer is greater than the bandgap of the light emitting layer.

[0101] In some example embodiments or any combination of example embodiments of the micro LED panel, the thickness of the regrowth layer is less than the thickness of the light emitting layer.

[0102] In some example embodiments or any combination of example embodiments of the micro LED panel, the thickness of the regrowth layer is not greater than 100 nm.

[0103] In some example embodiments or any combination of example embodiments of the micro LED panel, the electrical resistance of the regrowth layer is higher than the electrical resistance of the light emitting layer.

[0104] In some example embodiments or any combination of example embodiments of the micro LED panel, the regrowth layer is electrically non-conductive.

[0105] In some example embodiments or any combination of example embodiments of the micro LED panel, the dielectric layer is further formed at the bottom of the mesa structure; and the material of the dielectric layer is one or more of SiO2, SiNx, Al2O3, AIN, HfO2, TiO2, and / or ZrO2.

[0106] In some example embodiments or any combination of example embodiments of the micro LED panel, the bottom connection structure is formed in the dielectric layer.

[0107] In some example embodiments or any combination of example embodiments of the micro LED panel, the material of the first type of epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and / or AlGaInP, and the material of the second type of epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and / or AlGaInP.

[0108] Some example embodiments of the present disclosure provide a method of manufacturing a micro LED panel, the method comprising:

[0109] Step 1, providing a semiconductor substrate with an epitaxial structure, wherein the epitaxial structure comprises, from top to bottom, a first type epitaxial layer, a light emitting layer, and a second type epitaxial layer;

[0110] Step 2, forming a mesa structure by patterning the entire epitaxial structure from top to bottom;

[0111] Step 3, forming a regrowth layer on the entire sidewall of the light emitting layer, at least part of the sidewall of the first type epitaxial layer, and at least part of the sidewall of the second type epitaxial layer by an epitaxial material regrowth process;

[0112] Step 4, forming an opening in the regrowth layer on top of the first type epitaxial layer, forming a bottom contact in the opening on the surface of the first type epitaxial layer; then forming a dielectric layer on the regrowth layer, forming a second opening in the dielectric layer to expose the bottom contact;

[0113] Step 5, forming a bottom connection structure in the opening;

[0114] Step 6, bonding the first type epitaxial layer and the bottom connection structure with an IC backplane by inverting the semiconductor substrate; then removing the semiconductor substrate; and

[0115] Step 7, forming a top contact and a top conductive layer on the second type epitaxial layer.

[0116] In some example embodiments or any combination of example embodiments of the method of manufacturing a micro LED panel, in Step 3, the regrowth layer is further formed on the entire sidewall and top of the first type epitaxial layer and on the top of the semiconductor substrate; in Step 4, an opening is further formed in the regrowth layer on the first type epitaxial layer; and the temperature in the regrowth process is 400-1000°C and the regrowth time is 5-1000 seconds.

[0117] In some example embodiments or any combination of example embodiments, the method of manufacturing a micro LED panel further comprises: in Step 3, before forming the regrowth layer, forming a mask pattern covering the top and part of the sidewall of the first type epitaxial layer; and after forming the regrowth layer, removing the mask pattern.

[0118] In some example embodiments or any combination of example embodiments, the method of manufacturing a micro LED panel further comprises: in Step 3, before forming the regrowth layer, forming a mask pattern covering part of the sidewall of the second type epitaxial layer; and after forming the regrowth layer, removing the mask pattern.

[0119] In some example embodiments or any combination of the example embodiments, the method of manufacturing the micro LED panel further comprises: in step 3, before forming the regrowth layer, forming a first mask pattern covering the top and part of the sidewall of the first type epitaxial layer; forming a second mask pattern covering part of the sidewall of the second type epitaxial layer; and after forming the regrowth layer, removing the first mask pattern and the second mask pattern.

[0120] Some example embodiments of the present disclosure provide a micro LED panel comprising an array of micro LED structures, comprising:

[0121] at least one micro LED structure, wherein the micro LED structure comprises:

[0122] a mesa structure, wherein the mesa structure comprises, from bottom to top: a first type epitaxial layer, a light emitting layer, and a second type epitaxial layer; and

[0123] a regrowth layer, wherein the regrowth layer is grown on the entire sidewall of the mesa structure and completely fills in between adjacent mesa structures.

[0124] In some example embodiments of the micro LED panel or any combination of the example embodiments, a top width of the regrowth layer is the same as a top width of the space between adjacent mesa structures.

[0125] In some example embodiments of the micro LED panel or any combination of the example embodiments, a diameter of the mesa structure is no more than 3 pm.

[0126] In some example embodiments of the micro LED panel or any combination of the example embodiments, the light emitting layer comprises a top surface, an edge surface, and a bottom surface; and the regrowth layer is grown on the edge surface of the light emitting layer but not on the top surface and the bottom surface of the light emitting layer.

[0127] In some example embodiments of the micro LED panel or any combination of the example embodiments, the light emitting layer comprises a plurality of pairs of quantum wells.

[0128] In some example embodiments of the micro LED panel or any combination of the example embodiments, the light emitting layer has a straight line shape without any bending.

[0129] In some example embodiments of the micro LED panel or any combination of the example embodiments, a material of the regrowth layer with intrinsic doping ions is the same as a material of the first type epitaxial layer and / or a material of the second type epitaxial layer but without intentional doping ions.

[0130] In some example embodiments or any combination of example embodiments of the micro LED panel, the material of the regrowth layer is one or more of GaP, AlP, GaAs, InP, AlInP, GaInP, AlN, GaN, and / or InN.

[0131] In some example embodiments or any combination of example embodiments of the micro LED panel, the material of the regrowth layer is single crystalline, the material of the first type of epitaxial layer is single crystalline, and the material of the second type of epitaxial layer is single crystalline.

[0132] In some example embodiments or any combination of example embodiments of the micro LED panel, the bandgap of the regrowth layer is greater than the bandgap of the light emitting layer.

[0133] In some example embodiments or any combination of example embodiments of the micro LED panel, the thickness of the regrowth layer is less than the thickness of the light emitting layer.

[0134] In some example embodiments or any combination of example embodiments of the micro LED panel, the thickness of the regrowth layer is not greater than 100 nm.

[0135] In some example embodiments or any combination of example embodiments of the micro LED panel, the electrical resistance of the regrowth layer is higher than the electrical resistance of the light emitting layer.

[0136] In some example embodiments or any combination of example embodiments of the micro LED panel, the regrowth layer is electrically non-conductive.

[0137] In some example embodiments or any combination of example embodiments of the micro LED panel, the material of the first type of epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and / or AlGaInP, and the material of the second type of epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and / or AlGaInP.

[0138] In some example embodiments or any combination of example embodiments of the micro LED panel, the bottom of the mesa structure is further formed with a regrowth layer; and the bottom connection structure is formed in the regrowth layer and electrically connected to the first type of epitaxial layer.

[0139] In some example embodiments or any combination of example embodiments of the micro LED panel, a dielectric layer is further formed at the bottom of the mesa structure and the bottom of the regrowth layer; and the bottom connection structure is formed in the dielectric layer and electrically connected to the first type of epitaxial layer.

[0140] Some example embodiments of this disclosure provide a method of fabricating a micro LED panel, the method comprising:

[0141] Step 1, providing a semiconductor substrate with an epitaxial structure, wherein the epitaxial structure comprises, from top to bottom, a first type epitaxial layer, a light emitting layer, and a second type epitaxial layer;

[0142] Step 2, forming a mesa structure by patterning the epitaxial structure from top to bottom;

[0143] Step 3, forming a regrowth ring completely filled in the space of adjacent mesa structures and on top of the semiconductor substrate;

[0144] Step 4, forming an opening in the regrowth layer on the first type epitaxial layer, forming a bottom contact in the opening of the surface of the first type epitaxial layer;

[0145] Step 5, forming a bottom connection structure in the opening;

[0146] Step 6, bonding the bottom connection structure with an IC backplane by inverting the semiconductor substrate; then, removing the semiconductor substrate; and

[0147] Step 7, forming a top contact and a top conductive layer on the second type epitaxial layer.

[0148] In some example embodiments of the method of fabricating a micro LED panel or any combination of the example embodiments, in Step 3, the temperature in the regrowth process is 400-1000 °C, and the regrowth time is 5-1000 seconds.

[0149] Some example embodiments of this disclosure provide a method of fabricating a micro LED panel, the method comprising:

[0150] Step 1, providing a semiconductor substrate with an epitaxial structure, wherein the epitaxial structure comprises, from top to bottom, a first type epitaxial layer, a light emitting layer, and a second type epitaxial layer;

[0151] Step 2, forming a mesa structure by patterning the epitaxial structure from top to bottom;

[0152] Step 3, forming a regrowth layer completely filled in the space of adjacent mesa structures and on the entire sidewall of the epitaxial structure by an epitaxial material regrowth process;

[0153] Step 4, forming a dielectric layer on top of the first type epitaxial layer and on top of the regrowth layer;

[0154] Step 5, forming an opening in the dielectric layer on the first type epitaxial layer, forming a bottom contact in the opening of the surface of the first type epitaxial layer;

[0155] Step 6, forming a bottom connection structure in the opening;

[0156] Step 7, bonding the bottom connection structure with the IC backplane by inverting the semiconductor substrate; then, removing the semiconductor substrate; and

[0157] Step 8, forming a top contact and a top conductive layer on top of the second type of epitaxial layer.

[0158] In some example embodiments or any combination of the example embodiments of the method of manufacturing a micro-LED panel, in step 3, the temperature in the regrowth process is 400-1000 °C, and the regrowth time is 5-1000 seconds.

[0159] The micro-LED panel provided by the present disclosure can avoid non-radiative recombination at the sidewall of the micro-LED structure. In addition, compared with conventional micro-LEDs, the micro-LED structure of the present disclosure has high directional emission without other reflective structures, thereby simplifying the micro-LED structure and reducing the cost. In addition, the present disclosure can also inhibit non-radiative recombination at the surface of the micro-LED structure, thereby improving the image quality and increasing the EQE of the pixel.

[0160] Note that the various embodiments described above can be combined with any other embodiments described herein. The features and advantages described in the specification are not all inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes and can not have been selected to delineate or circumscribe the inventive subject matter. BRIEF DESCRIPTION OF DRAWINGS

[0161] For a more detailed understanding of the present disclosure, reference can be made to the more particular descriptions of various features illustrated in the accompanying drawings. However, the drawings are not to scale and, as such, are only intended to conceptually illustrate the relevant features of the present disclosure. The specification can enable one skilled in the art to make and use embodiments of the present disclosure for overcoming various

[0162] For convenience, "up" is used to mean away from the substrate of the light emitting structure shown in the figures, "down" means toward the substrate, and other directional terms such as top, bottom, above, below, under, beneath, and the like are similarly interpreted.

[0163] Figure 1 is a cross-sectional view of a micro-LED structure according to some embodiments of the present disclosure (e.g., Embodiment 1).

[0164] Figure 2 is a cross-sectional view of another micro-LED structure according to Embodiment 1 of the present disclosure;

[0165] Figures 3 to 14 FIG. 1 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 1). Figure 1 FIG. 2 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 1).

[0166] Figure 15 FIG. 3 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 1). Figure 2 FIG. 4 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 1).

[0167] Figure 16 FIG. 5 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 1).

[0168] Figure 17 FIG. 6 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 2).

[0169] Figures 18 to 27 FIG. 7 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 2). Figure 17 FIG. 8 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 2).

[0170] Figure 28 FIG. 9 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 3).

[0171] Figures 29 to 37 FIG. 10 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 3). Figure 28 FIG. 11 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 3).

[0172] Figure 38 FIG. 12 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 4).

[0173] Figures 39 to 46 FIG. 13 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 4). Figure 38 FIG. 14 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 4).

[0174] Figure 47 FIG. 15 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 5).

[0175] Figures 48 to 55 FIG. 16 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 5). Figure 47 FIG. 17 illustrates steps of a manufacturing method of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 5).

[0176] Accordingly, the dimensions of the various features can be arbitrarily expanded or reduced for clarity. In addition, some of the drawings can not depict all of the components of a given system, method or device. Finally, like reference numerals can be used to denote like features throughout the specification and figures. DETAILED DESCRIPTION

[0177] Many details are set forth in this description to provide a thorough understanding of the example embodiments shown in the figures. Some embodiments can be practiced without many of the details specified below, however, without parting from the scope of the claims below. In other instances, well-known processes, components and materials are not described in detail so as not to unnecessarily obscure aspects of the embodiments described herein.

[0178] As described above, to solve the problems in the related art, in some embodiments, a micro LED panel including a plurality of micro LED structures is disclosed in the present disclosure. The size of the micro LED panel is not greater than 1 cm. The micro LED structures are formed in an array form in the micro LED panel, having a resolution such as 720*480, 640*480, 1920*1080, 1280*720, 2k or 4k. The diameter of the micro LED structure is in the order of nanometer, such as 20nm to 100nm.

[0179] Figure 1 is a cross-sectional view of a micro LED structure according to some embodiments of the present disclosure. Referring to Figure 1The micro-LED structure is formed from the bottom to the top by the first type epitaxial layer 01, the light emitting layer 03 and the second type epitaxial layer 02. The first type and the second type are different conductive types, for example, the first type is P type, while the second type is N type. In another example, the first type is N type, while the second type is P type. In some embodiments, the material of the first type epitaxial layer 01 can be one or more of p-type GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, AlGaInP, AlP, InP, AlN and / or InN, or any combination thereof, preferably one or more of p-type GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP and / or AlGaInP, or any combination thereof, and the material of the second type epitaxial layer 03 can be one or more of n-type GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, AlGaInP, AlP, InP, AlN and / or InN, or any combination thereof, preferably one or more of n-type GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP and / or AlGaInP, or any combination thereof.

[0180] In some embodiments, the light emitting layer 03 is formed by multiple pairs of quantum well layers. The material of the quantum well layers can be one of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, AlGaInP, etc. In addition, the thickness of the first type epitaxial layer 01 is greater than the thickness of the second type epitaxial layer 02, and the thickness of the light emitting layer 03 is less than the thickness of the first type epitaxial layer 01. Preferably, the thickness of the first type epitaxial layer 01 is 700 nm to 2 μm, and the thickness of the second type epitaxial layer 02 is 100 nm to 200 nm. Preferably, the thickness of a single quantum well layer is not greater than 30 nm. In some examples, the light emitting layer 03 includes not more than three pairs of quantum well layers.

[0181] In some embodiments, the first type epitaxial layer 01 can have a plurality of stacked first type epitaxial sub-layers, and the second type epitaxial layer 02 can have a plurality of stacked second type epitaxial sub-layers. For example, the top layer of the first type epitaxial sub-layers is a P cap layer connected to the bottom of the light emitting layer 03, and the bottom layer of the second type epitaxial sub-layers is an N cap layer connected to the top of the light emitting layer 03, for protecting the quantum well layers from being damaged.

[0182] In addition, the first type epitaxial layer 01 includes one or more mirror layers 011 Figure 1The mirror layer 011 can be formed on the bottom surface of the first type epitaxial layer 01 or inside the first type epitaxial layer 01. The material of the mirror layer is a combination of dielectric material and metal material. In addition, the dielectric material is SiO2 or SiNx, where x is a positive integer; preferably, the metal material is Au or Ag. In some embodiments, a plurality of mirror layers 011 are horizontally formed one after another in the first type epitaxial layer 01 at different horizontal height positions, thereby dividing the first type epitaxial layer 01 into a plurality of layers.

[0183] In some embodiments, the top contact 09 is formed on the top surface of the second type epitaxial layer 02. The conduction type of the top contact 09 is the same as the conduction type of the second type epitaxial layer 02, such as the second type is n-type, the top contact 09 is an n-type top contact; or the second type is p-type, the top contact 09 is a p-type top contact. In some embodiments, the top contact 09 is made of metal or metal alloy, such as AuGe, AuGeNi, etc. The top contact 09 is used to form an ohmic contact between the top conductive layer 08 and the second type epitaxial layer 02, so as to optimize the electrical characteristics of the micro-LED. The diameter of the top contact 09 is about 20-50 nm, and the thickness of the top contact 09 is about 10-20 nm. In some embodiments, the top conductive layer 08 is transparent and conductive, such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), etc.

[0184] In some embodiments, the bottom contact 06 is formed at the bottom surface of the first type epitaxial layer 01. The conductive type of the bottom contact 06 is the same as the conductive type of the first type epitaxial layer 01, such as, the first type epitaxial layer 01 is P-type, the bottom contact 06 is also P-type. In addition, since light is emitted upward or downward from the LED mesa structure composed of or including the first type epitaxial layer 01, the second type epitaxial layer 02 and the light emitting layer 03, the diameter of the bottom contact 06 is larger than the diameter of the top contact 09, while the diameter of the top contact 09 can be as small as possible, thus, the top contact 09 also serves as a point on the top surface of the second type epitaxial layer 02. For example, the width of the top contact 09 is less than 1 / 5, 1 / 6, 1 / 10 or 1 / 20 of the width of the second type epitaxial layer 02 or the mesa. In some embodiments, the diameter of the bottom contact 06 can also be equal to or smaller than the diameter of the top contact 09. A bottom connection structure 07 is formed at the bottom of the bottom contact 06. The bottom connection structure 07 is used to connect with a bottom electrode such as a contact pad in an IC backplane. In addition, the diameter of the bottom connection structure 07 is 20 nm to 1 μm. Preferably, the diameter of the bottom connection structure 07 is 800 nm to 1 μm. In addition, the center of the bottom contact 06 is aligned with the center of the top contact 09 in the vertical direction. In some embodiments, the material of the bottom contact 06 and the bottom connection structure 07 is a transparent conductive material such as ITO or FTO, etc. In addition, in some embodiments, the material of the bottom contact 06 and the bottom connection structure 07 is not transparent. The material of the bottom contact 06 and the bottom connection structure 07 can be a conductive metal. Preferably, the material of the bottom contact 06 can be at least one selected from Au, Zn, Be, Cr, Ni, Ti, Ag and Pt. The material of the bottom connection structure 07 can be at least one selected from Au, Zn, Be, Cr, Ni, Ti, Ag and Pt.

[0185] As shown in FIG. 1, the center of the bottom contact 06 is aligned with the center of the first type epitaxial layer 01 in the vertical direction. However, in another embodiment, the center of the bottom contact 06 is not aligned with the center of the first type epitaxial layer 01 in the vertical direction. Figure 1

[0186] ​In some embodiments, in order to avoid non-radiative recombination and surface carrier loss at the sidewall of the mesa structure, a regrowth layer 04 is formed on the sidewall of the light emitting layer 03, even on the sidewall of the first type epitaxial layer 01 and the sidewall of the second type epitaxial layer 02 by a regrowth process. For example, the regrowth layer can be grown on part of the sidewall of the light emitting layer 03 or the entire sidewall of the light emitting layer. "Entire" means substantially or the entire part. In addition, the regrowth layer 04 can also be formed on part of the first type epitaxial layer 01 or the entire sidewall of the first type epitaxial layer 01; and / or, the regrowth layer 04 can also be formed on part of the second type epitaxial layer 02 or the entire sidewall of the second type epitaxial layer 02.

[0187] In some embodiments, the regrowth layer 04 is grown on at least part of the sidewall of the first type epitaxial layer 01, the entire sidewall of the light emitting layer 03, and at least part of the sidewall of the second type epitaxial layer 02. In some embodiments, the regrowth layer 04 is grown on the entire sidewall of the first type epitaxial layer 01, the entire sidewall of the light emitting layer 03, and the entire sidewall of the second type epitaxial layer 02. In another embodiment, the regrowth layer 04 is grown on part of the sidewall of the first type epitaxial layer 01, the entire sidewall of the light emitting layer 03, and the entire sidewall of the second type epitaxial layer 02. In some embodiments, the regrowth layer 04 is grown on the entire sidewall of the first type epitaxial layer 01, the entire sidewall of the light emitting layer 03, and part of the sidewall of the second type epitaxial layer 02. In another embodiment, the regrowth layer 04 is grown on part of the sidewall of the first type epitaxial layer 01, the entire sidewall of the light emitting layer 03, and part of the sidewall of the second type epitaxial layer 02.

[0188] The regrowth layer 04 on the sidewall of the light emitting layer 03 is not parallel to the extension horizontal direction of the light emitting layer 03, as shown in Figure 1 In addition, the light emitting layer 03 includes a top surface, an edge surface, and a bottom surface; and the regrowth layer 04 is grown only on the edge surface of the light emitting layer 03, but not on the top surface and the bottom surface of the light emitting layer 03. Preferably, the inclination angle of the regrowth layer 04 on the sidewall of the light emitting layer is 30° to 90° relative to the horizontal direction of the light emitting layer 03. In other words, the regrowth layer 04 is grown on the end surface of the light emitting layer 03, but not on the top and bottom of the light emitting layer 03. In addition, the light emitting layer 03 includes a plurality of pairs of quantum wells; the regrowth layer 04 is not parallel to the surface of each pair of the plurality of pairs of quantum wells. Here, the light emitting layer 03 has a straight line shape without any bending. Preferably, the diameter of the mesa structure is not greater than 3 μm.

[0189] Here, the material of the regrowth layer 04 is the same as the material of the first type epitaxial layer 01 and / or the material of the second type epitaxial layer 02, but without intentional non-intrinsic dopant ions. For example, when the material of the first type epitaxial layer 01 and the material of the second type epitaxial layer 02 are the same, and the intentional ion doping levels of the material of the first type epitaxial layer 01 and the material of the second type epitaxial layer 02 are different, the material of the regrowth layer 04 can be the same as the material of the underlying first type epitaxial layer 01 and the second type epitaxial layer 02, but without intentional non-intrinsic dopant ions. In another example, when the material of the first type epitaxial layer 01 and the material of the second type epitaxial layer 02 are not the same, and the intentional ion doping levels of the material of the first type epitaxial layer 01 and the material of the second type epitaxial layer 02 are different, the material of the regrowth layer 04 can be the same as the material of the first type epitaxial layer 01 or the second type epitaxial layer 02, but without intentional non-intrinsic dopant ions. The light emitting layer is the active region of the PN junction formed by the first type epitaxial layer 01 and the second type epitaxial layer 02, and can be considered to be composed of two materials of the first type epitaxial layer 01 and the second type epitaxial layer 02. In some embodiments, the portion of the material of the regrowth layer covering the first type epitaxial layer 01 is the same as the underlying first type epitaxial layer 01, but without the non-intrinsic intentional doping of the first type epitaxial layer 01, and the portion of the material of the regrowth layer covering the second type epitaxial layer 02 is the same as the underlying second type epitaxial layer 02, but without the non-intrinsic intentional doping of the second type epitaxial layer 02. In some embodiments, the regrowth layer 04 can have some intrinsic doping level or no doping level. In some embodiments, the material growth parameters, such as ambient / gas pressure, power, and material used for the regrowth process, are the same or similar to the material growth parameters of the first type epitaxial layer 01 and / or the second type epitaxial layer 02. The material of the regrowth layer 04 must be lattice matched to the light emitting layer 03, the first type epitaxial layer 01, and / or the second type epitaxial layer 02. Preferably, the material of the regrowth layer 04 is single crystalline, the material of the first epitaxial layer 01 is single crystalline, and the material of the second epitaxial layer 02 is single crystalline. Furthermore, the material of the regrowth layer 04 is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, AlGaInP, AlP, InP, AlN, and / or InN, or any combination thereof, preferably one or more of GaP, AlP, GaAs, InP, AlInP, GaInP, AlN, GaN, and / or InN, or any combination thereof. In another embodiment, the material of the regrowth layer 04 has no intentional dopant ions, and is different from the material of the first type epitaxial layer or the material of the second type epitaxial layer 02.

[0190] The regrowth layer 04 has a higher electrical resistance than the light emitting layer 03, and the regrowth layer 04 is not electrically conductive, thereby ensuring proper operation of the micro-LED structure and preventing the diffusion of charge carriers outside the light emitting layer 03. Preferably, the bandgap of the regrowth layer 04 is greater than the bandgap of the light emitting layer 03. Furthermore, the thickness of the regrowth layer 04 is less than the thickness of the light emitting layer 03, preferably the thickness of the regrowth layer 04 is not greater than 10 nm or 100 nm. In another embodiment, the thickness of the regrowth layer 04 is equal to or greater than the thickness of the light emitting layer 03.

[0191] In the following, details of the micro-LED panel and the manufacturing method of the micro-LED panel will be described according to the accompanying drawings.

[0192] Embodiment 1

[0193] The micro-LED panel of embodiment 1 comprises an array of micro-LED structures. Referring to Figure 1 , the micro-LED structure in the micro-LED panel comprises: a mesa structure comprising 01, 02 and 03, a regrowth layer 04, a bottom contact 06, a bottom connection structure 07, an IC backplane 00, a top contact 09 and a top conductive layer 08. A dielectric layer 05 is formed between adjacent mesa structures.

[0194] The mesa structure comprises from bottom to top: a first type epitaxial layer 01, a light emitting layer 03 and a second type epitaxial layer 02. The regrowth layer 04 is grown on the entire sidewall of the first type epitaxial layer 01, the entire sidewall of the light emitting layer 03 and part of the sidewall of the second type epitaxial layer 02. Furthermore, the regrowth layer 04 is very thin, such as 5 nm, so in some embodiments the regrowth layer 04 is transparent.

[0195] A dielectric layer 05 is formed between adjacent mesa structures. Furthermore, the dielectric layer 05 is formed on the surface of the regrowth layer 04 between adjacent mesa structures. The top end of the regrowth layer 04 further protrudes into the dielectric layer 05. Preferably, the top end of the regrowth layer 04 is connected to the adjacent light emitting layer 03 and the adjacent first type epitaxial layer 01. In addition, the top end of the regrowth layer 04 protruding into the dielectric layer 05 is parallel to the bottom surface of the second type epitaxial layer 02. Preferably, the material of the dielectric layer 05 is one or more of SiO2, SiNx, Al2O3, AlN, HfO2, TiO2 and / or ZrO2, etc. In addition, in some embodiments, the material of the dielectric layer 05 is transparent.

[0196] Here, the top of the regrowth layer 04 is higher than the top of the light emitting layer 03, and the bottom of the regrowth layer 04 is aligned with the bottom of the first type epitaxial layer 01, further, the regrowth layer 04 is formed at the bottom of the first type epitaxial layer 01. An opening is formed in the regrowth layer 04 and the dielectric layer 05. A bottom contact 06 is formed in the opening at the bottom of the first type epitaxial layer 01. And a bottom connection structure 07 is formed in the opening and at the bottom of the bottom contact 06.

[0197] In another embodiment, referring to Figure 2 , the regrowth layer 04 is grown on the partial sidewall of the first type epitaxial layer 01, the entire sidewall of the light emitting layer 03, and the partial sidewall of the second type epitaxial layer 02. The top of the regrowth layer 04 is higher than the top of the light emitting layer 03, and the bottom of the regrowth layer 04 is lower than the bottom of the light emitting layer 03. An opening is formed in the dielectric layer 05. A bottom contact 06 is formed in the opening at the bottom of the first type epitaxial layer 01. And a bottom connection structure 07 is formed in the opening and at the bottom of the bottom contact 06.

[0198] In addition, a top contact 09 and a top conductive layer 08 are formed on the top of the second type epitaxial layer 02. In some embodiments, the top conductive layer 08 is formed continuously on the entire micro-LED panel in this embodiment. In another embodiment, referring to Figure 16 , the top conductive layer 08 is formed on the top contact 09 and the partial top surface of the second type epitaxial layer 02.

[0199] In some embodiments, the manufacturing method of the aforementioned micro-LED panel in Embodiment 1 comprises the following steps.

[0200] Referring to Figure 3 , step 1 comprises providing a semiconductor substrate 00' with an epitaxial structure.

[0201] Here, the epitaxial structure comprises, from top to bottom, a first type epitaxial layer 01, a light emitting layer 03, and a second type epitaxial layer 02. The material of the semiconductor substrate 00' can be GaN, GaAs, etc. The epitaxial structure is grown on the substrate 00'.

[0202] Referring to Figure 4 , step 2 comprises forming a mesa structure by patterning the epitaxial structure.

[0203] Here, the epitaxial structure is etched from top to bottom by a conventional plasma etching process.

[0204] Referring to Figure 5 , step 3 comprises forming a first mask pattern R1 on the semiconductor substrate 00' to cover the sidewall of the first type epitaxial layer 01 and the sidewall of the light emitting layer 03.

[0205] Here, the first mask pattern R1 is formed by a conventional photolithography process. The first mask pattern R1 is formed to cover the sidewall of the light emitting layer 03, the top and sidewall of the first type epitaxial layer 01, and a portion of the second type epitaxial layer 02.

[0206] Referring to Figure 6 , step 4 comprises depositing a first dielectric layer 05’ on the substrate 00’ between the adjacent mesa structures, and the top of the first dielectric layer 05’ is lower than the bottom of the light emitting layer 03.

[0207] Here, the first dielectric layer 05’ is deposited on the semiconductor substrate 00’ and on the surface of the first mask pattern R1 by a conventional vapor deposition process under the protection of the first mask pattern R1. The top of the first dielectric layer 05’ is lower than the bottom of the light emitting layer 03.

[0208] The bottom of the first mask pattern R1 is lower than the bottom of the light emitting layer 03, so the top of the first dielectric layer 05’ is lower than the top of the second type epitaxial layer 02, and then the regrowth layer 04 can be formed on the entire sidewall of the first type epitaxial layer 01, the entire sidewall of the light emitting layer 03, and the partial sidewall of the second type epitaxial layer 02. Therefore, the position of the regrowth layer 04 is determined by the bottom of the first mask pattern R1.

[0209] Then, step 4 additionally comprises removing the first mask pattern R1.

[0210] Here, the first mask pattern R1 is removed by a chemical etching process.

[0211] Referring to Figure 7 , step 5 comprises forming a regrowth layer 04 on the entire sidewall of the light emitting layer 03 and at least a portion of the sidewall of the first type epitaxial layer 01 by an epitaxial material regrowth process.

[0212] Here, the regrowth layer 04 is directly grown on the entire sidewall of the light emitting layer 03, the top and entire sidewall of the first type epitaxial layer 01, and the partial sidewall of the second type epitaxial layer 02, and deposited on the top surface of the first dielectric layer 01. During this regrowth, the temperature is 400°C to 1000°C, and the regrowth time is 5 seconds to 1000 seconds. The material used for the regrowth process is the same as the material of the first type epitaxial layer 01 and / or the material of the second type epitaxial layer 02, but without intentional doping ions. In some embodiments, in the case where the top of the first dielectric layer 01 is lower than the bottom of the light emitting layer 03, the regrowth layer 04 is also formed on at least a portion of the sidewall of the second type epitaxial layer 02.

[0213] In another embodiment, referring to Figure 15In step 5, before growing the regrowth layer, step 5 further comprises: forming a second mask pattern R2 covering the top and part of the sidewall of the first type epitaxial layer 01; the regrowth layer 04 is formed on the entire sidewall of the light emitting layer 03 and part of the sidewall of the first type epitaxial layer 01. After forming the regrowth layer 04, step 5 further comprises: removing the second mask pattern R2. Thus, referring to Figure 2 The regrowth layer 04 can be formed on part of the first type epitaxial layer 01, on the entire sidewall of the light emitting layer 03, and on part of the sidewall of the second type epitaxial layer 02. Thus, the position of the regrowth layer 04 is determined by the bottom position of the second mask pattern R2.

[0214] Referring to Figure 10 Step 7 comprises forming the bottom contact 06 in the regrowth layer 04 on the top surface of the first type epitaxial layer 01, and forming the second dielectric layer 02 on the regrowth layer 04, the second dielectric layer 02 having an opening exposing the top of the bottom contact 06.

[0215] Here, referring to Figure 8 An opening is formed in the regrowth layer 04 on the top surface of the first type epitaxial layer 01 by a plasma etching process. Then, referring to Figure 9 First, a bottom contact layer 06 is deposited in the opening by covering other areas except the first opening with a mask, and the bottom contact layer 06 is connected to the first type epitaxial layer 01, and the mask is removed. Next, referring to Figure 10 The second dielectric layer 05” is deposited on the surface of the regrowth layer 04 by a conventional chemical vapor deposition process. Then, another opening is formed in the second dielectric layer 05” to expose the top of the bottom contact 06.

[0216] In another embodiment, step 7 comprises: forming the second dielectric layer 05” on the regrowth layer 04, and forming an opening in the second dielectric layer 05” on the first type epitaxial layer 01, and filling the bottom contact 06 in the opening. Here, the second dielectric layer 05” is deposited on the surface of the regrowth layer 04 by a conventional chemical vapor deposition process. Then, an opening is formed in the second dielectric layer 02 and in the regrowth layer 04 on the top of the first type epitaxial layer 01. Next, the bottom contact 06 is deposited into the opening and connected to the first type epitaxial layer 01.

[0217] In another embodiment, the bottom contact 06 can be formed before depositing the regrowth layer 04. Then, the regrowth layer 04 is deposited on the sidewall of the light emitting layer 03, the sidewall and top of the first type epitaxial layer 01, and the bottom contact 06. Next, the second dielectric layer 02 is formed on the regrowth layer 04. Finally, an opening is formed in the second dielectric layer 02 and the regrowth layer 04 to expose the bottom contact 06.

[0218] Referring to Figure 11Step 8 includes forming a bottom connection structure 07 in the opening.

[0219] Here, the material of the bottom connection structure 07 is deposited into the opening and on the bottom contact 06 by a conventional vapor deposition process.

[0220] Referring to Figure 12 Step 9 includes bonding the first type epitaxial layer 01 and the bottom connection structure 07 to the IC backplane 00 by inverting the semiconductor substrate 00’. Then, the semiconductor substrate 00’ is removed.

[0221] Here, the semiconductor substrate 00’ with the epitaxial structure is first inverted. Then, the bottom connection structure 07 is bonded to the pads of the IC backplane 00. After the bonding process, the semiconductor substrate 00’ is removed by a conventional removal process such as a laser lift-off method.

[0222] Referring to Figure 14 Step 10 includes forming a top contact 09 and a top conductive layer 08 on the second type epitaxial layer 02.

[0223] Here, referring to Figure 13 The top contact 09 is deposited on top of the second type epitaxial layer 02, where other areas are protected with a mask, and then the mask is removed. Then, referring to Figure 14 The top conductive layer 08 is deposited on the second type epitaxial layer 02 by a conventional vapor deposition process.

[0224] In some embodiments herein, Figure 1 The dielectric layer 05 in

[0225] Embodiment 2

[0226] The micro-LED panel of Embodiment 2 includes an array of micro-LED structures. Figure 17 is a cross-sectional structure diagram of a micro-LED panel according to some embodiments of the present disclosure (e.g., Embodiment 2).

[0227] Referring to Figure 17 The micro-LED structure includes: a mesa structure, a regrowth layer 04, a bottom contact 06, a bottom connection structure 07, an IC backplane 00, a top contact 09, and a top conductive layer 08. A dielectric layer 05 is formed between adjacent mesa structures. Here, the material of the dielectric layer 05 is one or more of SiO2, SiNx, Al2O3, AlN, HfO2, TiO2, and / or ZrO2, etc. In another embodiment, the regrowth layer 04 is filled between the adjacent light emitting layer 03 and the second type epitaxial layer 02, like a ring around the mesa structure.

[0228] The mesa structure comprises from bottom to top: a first type epitaxial layer 01, a light emitting layer 03, and a second type epitaxial layer 02. A regrowth layer 04 is grown at least on the sidewall of the light emitting layer 03. In addition, the regrowth layer 04 is grown on the entire sidewall of the light emitting layer 03, a portion of the first type epitaxial layer 01, and the entire sidewall of the second type epitaxial layer 02. The tilt angle of the regrowth layer 04 on the sidewall of the light emitting layer 03 is 30 degrees to 90 degrees relative to the light emitting layer 03. The top end of the regrowth layer 03 further protrudes along the top surface of the dielectric layer 05. The regrowth layer 04 along the dielectric layer 05 is parallel to the bottom surface of the second type epitaxial layer 02. In addition, the top end of the regrowth layer 04 protruding along the dielectric layer 05 and on top thereof is connected to the adjacent light emitting layer 03 and the adjacent second type epitaxial layer 02. Furthermore, the regrowth layer 04 is very thin, no more than 10 nm, such as 5 nm, so the regrowth layer 04 is transparent in some embodiments.

[0229] In addition, the bottom of the regrowth layer 04 is lower than the bottom of the light emitting layer 03. And the top of the regrowth layer 04 is aligned with the top of the second type epitaxial layer 02.

[0230] The dielectric layer 05 is also formed at the bottom of the mesa structure. An opening is formed in the dielectric layer 05. A bottom contact 06 is formed in the opening at the bottom of the first type epitaxial layer 01. And, a bottom connection structure 07 is formed in the opening at the bottom of the bottom contact 06. In addition, in some embodiments, the material of the dielectric layer 05 is transparent.

[0231] In addition, a top contact 09 and a top conductive layer 08 are formed on the top of the second type epitaxial layer 02. In some embodiments, the top conductive layer 08 is formed continuously on the entire micro-LED panel. In another embodiment, the top conductive layer 08 is formed on the top contact and a portion of the top surface of the second type epitaxial layer 02.

[0232] The manufacturing method of the aforementioned micro-LED panel in embodiment 2 comprises the following steps.

[0233] Figures 18 to 27 The manufacturing method of the micro-LED panel in Figure 17 is illustrated according to some embodiments (e.g., embodiment 2) of the present disclosure.

[0234] Referring to Figure 18 , step 1 comprises providing a semiconductor substrate 00' with an epitaxial structure.

[0235] Here, the epitaxial structure comprises from top to bottom: a first type epitaxial layer 01, a light emitting layer 03, and a second type epitaxial layer 02. The material of the semiconductor substrate 00' can be GaN, GaAs, etc., and the epitaxial structure is grown on the substrate 00'.

[0236] Referring to Figure 19Step 2 includes forming mesa structures by patterning the epitaxial structure.

[0237] Here, the epitaxial structure is etched from top to bottom by a conventional plasma etching process.

[0238] Referring to Figure 20 Step 3 includes forming a mask pattern on the semiconductor substrate 00’ to cover the first type epitaxial layer 01.

[0239] Here, the mask pattern R1 covering the top and part of the sidewall of the first type epitaxial layer 01 is formed by a photolithography method. The material of the mask pattern R1 is photoresist. In another embodiment, the material of the mask pattern R1 can be another material, such as a dielectric material.

[0240] Here, the bottom of the mask pattern R1 is higher than the bottom of the first type epitaxial layer 01, so the regrowth layer 04 is further formed on a part of the first type epitaxial layer 01. Therefore, the position of the regrowth layer 04 is determined by the bottom position of the mask pattern R1.

[0241] Referring to Figure 21 Step 4 includes forming a regrowth layer 04 on the sidewall of the light emitting layer 03, the sidewall of the second type epitaxial layer 02 and part of the sidewall of the first type epitaxial layer 01 by an epitaxial material regrowth process.

[0242] Here, the regrowth layer 04 is grown on the sidewall of the light emitting layer 03, the sidewall of the second type epitaxial layer 02, part of the sidewall of the first type epitaxial layer 01, and deposited on the exposed top surface of the semiconductor substrate 00”. During this regrowth process, the temperature is 400-1000°C, and the regrowth time is 5-1000 seconds. The material used for the regrowth process is the same as that of the first type epitaxial layer and the second type epitaxial layer, but without intentional doping ions.

[0243] Referring to Figure 22 Step 5 includes removing the mask pattern R1.

[0244] Here, the mask pattern R1 is removed by a conventional chemical etching process.

[0245] Referring to Figure 24 Step 6 includes forming a bottom contact 06 on the surface of the first type epitaxial layer 01, and forming a dielectric layer 05 on the top and sidewall of the regrowth layer 04 and the first type epitaxial layer 01 between adjacent mesa structures; wherein the dielectric layer 05 has an opening exposing the top of the bottom contact 06.

[0246] Here, referring to Figure 23 The bottom contact 06 is first formed on the top of the mesa structure. Then, referring to Figure 24The dielectric layer 05 is deposited on the surface of the regrowth layer 04 and on the sidewalls and top of the first type epitaxial layer 01 by a conventional chemical vapor deposition process. Then, an opening is formed in the dielectric layer 05 on the top of the first type epitaxial layer 01 by a dry etching process. Next, the opening is formed by a plasma etching process to expose the bottom contact 06.

[0247] In some embodiments, step 6 comprises the following steps: first, an initial dielectric layer is deposited on the regrowth layer 04, on the sidewalls and top of the first type epitaxial layer 01. Then, the top of the initial dielectric layer is planarized to the top of the first type epitaxial layer 01, and a bottom contact 06 is deposited on the first type epitaxial layer 01. Then, another dielectric layer is deposited on the initial dielectric layer and on the sidewalls and top of the mesa structure, and the dielectric layer covers the top contact 06 to form the dielectric layer 05. Next, an opening is formed in the dielectric layer and exposes the bottom contact 06. The dielectric layer 05 is formed by the initial dielectric layer and the other dielectric layer.

[0248] Referring to Figure 25 Step 7 comprises forming a bottom connection structure 07 in the opening.

[0249] Here, the material of the bottom connection structure 07 is deposited into the opening and on the bottom contact 06 by a conventional vapor deposition process.

[0250] Referring to Figure 26 Step 8 comprises bonding the first type epitaxial layer 01 and the bottom connection structure 07 to the IC backplane 00 by inverting the semiconductor substrate 00’. Then, the semiconductor substrate 00’ is removed.

[0251] Here, the semiconductor substrate 00’ with the epitaxial structure is first inverted. Then, the bottom connection structure 07 is bonded to the pads of the IC backplane 00. After the bonding process, the semiconductor substrate 00’ is removed by a conventional removal process such as a laser lift-off method.

[0252] Referring to Figure 27 Step 9 comprises forming a top contact 09 and a top conductive layer 08 on the second type epitaxial layer 02.

[0253] Here, the top contact 09 is deposited on the top of the second type epitaxial layer 02, wherein other areas are protected with a mask. Then, the top conductive layer 08 is deposited on the second type epitaxial layer 02 by a conventional vapor deposition process.

[0254] Embodiment 3

[0255] To solve the problems in the related art, in embodiments of the present application, a micro LED panel is provided.

[0256] The micro-LED panel of Example 3 includes a micro-LED structure array. Figure 28 This is a cross-sectional structural diagram of a micro LED panel according to some embodiments of the present disclosure (e.g., embodiment 3).

[0257] Reference Figure 28 The micro-LED structure includes: a mesa structure, a regenerated layer 04, a bottom contact 06, a bottom connection structure 07, an IC backplane 00, a top contact 09, and a top conductive layer 08. The mesa structure, from bottom to top, includes: a first type epitaxial layer 01, a light-emitting layer 03, and a second type epitaxial layer 02. Here, the regenerated layer 04 is grown on the entire sidewall of the first type epitaxial layer 01, the entire sidewall of the light-emitting layer 03, and the entire sidewall of the second type epitaxial layer 02. In some embodiments, the regenerated layer 04 is grown on at least a portion of the sidewall of the first type epitaxial layer 01, the entire sidewall of the light-emitting layer 03, and at least a portion of the sidewall of the second type epitaxial layer 02. Furthermore, in some embodiments, the regenerated layer 04 is grown on the entire sidewall of the first type epitaxial layer 01, the entire sidewall of the light-emitting layer 03, and the entire sidewall of the second type epitaxial layer 02. In another embodiment, the regenerated layer 04 is grown on a portion of the sidewalls of the first type epitaxial layer 01, the entire sidewalls of the light-emitting layer 03, and the entire sidewalls of the second type epitaxial layer 02. In some embodiments, the regenerated layer 03 is grown on the entire sidewalls of the first type epitaxial layer 01, the entire sidewalls of the light-emitting layer 03, and a portion of the sidewalls of the second type epitaxial layer 02. In another embodiment, the regenerated layer 03 is grown on a portion of the sidewalls of the first type epitaxial layer 01, the entire sidewalls of the light-emitting layer 03, and a portion of the sidewalls of the second type epitaxial layer 02.

[0258] A dielectric layer 05 is formed between adjacent mesa structures. The dielectric layer 05 is also formed at the bottom of the mesa structures. Preferably, the material of the dielectric layer 05 is one or more of SiO2, SiNx, Al2O3, AlN, HfO2, TiO2, and / or ZrO2. Additionally, in some embodiments, the material of the dielectric layer 05 is transparent.

[0259] A bottom contact 06 and a bottom connection structure 07 are formed at the bottom of the first type epitaxial layer 01 in the dielectric layer 05. Additionally, a top contact 09 and a top conductive layer 08 are formed on top of the second type epitaxial layer 02. In some embodiments, the top conductive layer 08 is continuously formed over the entire microLED panel. In another embodiment, the top conductive layer 08 is formed on a portion of the top surface of the top contact 09 and the second type epitaxial layer 02.

[0260] The top end of the regrowth layer 04 further protrudes along the top surface of the dielectric layer 05. In addition, the regrowth layer 04 protruding along the dielectric layer 05 is parallel to the top surface of the dielectric layer 05. Preferably, the regrowth layer 04 protruding along the top of the dielectric layer 05 is connected to the adjacent second-type epitaxial layer 02. In addition, the regrowth layer 04 is also formed at the bottom surface of the first-type epitaxial layer 01. The bottom contact 06 is also formed in the regrowth layer 04.

[0261] The manufacturing method of the micro-LED panel in the above embodiment 3 comprises the following steps.

[0262] Figures 29 to 37 The manufacturing method of the micro-LED panel in the above embodiment 3 comprises the following steps. Figure 28 The manufacturing method of the micro-LED panel in the above embodiment 3 comprises the following steps.

[0263] Referring to Figure 29 , step 1 comprises providing a semiconductor substrate 00' with an epitaxial structure. The epitaxial structure comprises, from top to bottom, a first-type epitaxial layer 01, a light-emitting layer 03, and a second-type epitaxial layer 02.

[0264] Here, the epitaxial structure comprises, from top to bottom, a first-type epitaxial layer 01, a light-emitting layer 03, and a second-type epitaxial layer 02. The material of the semiconductor substrate 00' can be GaN, GaAs, etc., and the epitaxial structure is grown on the semiconductor substrate 00'.

[0265] Referring to Figure 30 , step 2 comprises forming a mesa structure by patterning the entire epitaxial structure from top to bottom.

[0266] Here, the epitaxial structure is etched from top to bottom by a conventional plasma etching process.

[0267] Referring to Figure 31 , step 3 comprises forming a regrowth layer 04 on the entire sidewall of the light-emitting layer 03, on at least a portion of the sidewall of the first-type epitaxial layer 01, and on at least a portion of the sidewall of the second-type epitaxial layer 02 by an epitaxial material regrowth process.

[0268] Here, the regrowth layer 04 is regrown on the entire sidewall of the light-emitting layer 03, the first-type epitaxial layer 01, and the second-type epitaxial layer 02. In addition, the regrowth layer 04 is also formed on the top surface of the first-type epitaxial layer 01 and on the exposed top surface of the semiconductor substrate 00'. In this regrowth process, the temperature is 400-1000°C, and the regrowth time is 5-1000 seconds. The material used for the regrowth process is the same as that of the first-type epitaxial layer and the second-type epitaxial layer, but without intentional doping ions.

[0269] In another embodiment, the regrowth layer 04 is also grown on at least a portion of the sidewall of the second type epitaxial layer 02, the entire sidewall of the first type epitaxial layer 01, and the entire sidewall of the light emitting layer 03, but not on the semiconductor substrate 00’. Thus, before forming the regrowth layer 04 in step 3, step 3 further comprises forming a mask pattern covering a portion of the sidewall of the second type epitaxial layer 02. Then, the regrowth layer is grown on the entire sidewall of the light emitting layer 03, the entire sidewall of the first type epitaxial layer 01, and a portion of the sidewall of the second type epitaxial layer 02. After forming the regrowth layer 04, step 3 further comprises removing the mask pattern.

[0270] In some embodiments, the regrowth layer 04 is also grown on at least a portion of the sidewall of the first type epitaxial layer 01, the entire sidewall of the light emitting layer 03, and the entire sidewall of the second type epitaxial layer 02, but not on the top of the first type epitaxial layer 01. Thus, before forming the regrowth layer 04 in step 3, step 3 further comprises forming a mask pattern covering the top and a portion of the sidewall of the first type epitaxial layer 01. Then, the regrowth layer 04 is grown on the entire sidewall of the light emitting layer 03, the entire sidewall of the second type epitaxial layer 02, and a portion of the sidewall of the first type epitaxial layer 01. After forming the regrowth layer 04, step 3 further comprises removing the mask pattern.

[0271] In some embodiments, the regrowth layer 04 is grown on at least a portion of the sidewall of the first type epitaxial layer 01 and at least a portion of the second type epitaxial layer 02, on the entire sidewall of the light emitting layer 03, but not on the top of the first type epitaxial layer 01 and the top of the substrate 00’. Thus, before forming the regrowth layer 04, step 3 further comprises forming a first mask pattern covering the top and a portion of the sidewall of the first type epitaxial layer 01, and covering a portion of the sidewall of the second type epitaxial layer 02 and the exposed top surface of the semiconductor substrate 00’. Then, the regrowth layer 04 is grown on the entire sidewall of the light emitting layer 03, the entire sidewall of the second type epitaxial layer 02, and the sidewall of the first type epitaxial layer 01. After forming the regrowth layer 04, step 3 further comprises removing the mask pattern.

[0272] Referring to Figure 32 to 24 , step 4 comprises forming an opening in the regrowth layer 04 on the top of the first type epitaxial layer 01, and forming a bottom contact 06 on the surface of the first type epitaxial layer 01 in the opening. Then, a dielectric layer 05 is formed on the regrowth layer 04, and a second opening is formed in the dielectric layer 05 to expose the bottom contact 06.

[0273] Here, referring to Figure 32 , a first opening is formed in the regrowth layer 04 on the top surface of the first type epitaxial layer 01. Then, referring to Figure 33 , a bottom contact 06 is deposited in the first opening; referring toFigure 34 A dielectric layer 05 is deposited on the regrown layer 04. Then, a second opening is formed in the dielectric layer 05 on top of the bottom contact 06 to expose the bottom contact 06.

[0274] In another embodiment, a dielectric layer is first deposited on the regrown ring, on the sidewalls and top of the first type epitaxial layer. Then, an opening is formed in the dielectric layer on the first type epitaxial layer. Next, a bottom contact is formed in the opening and connected to the first type epitaxial layer.

[0275] In some embodiments, step 4 comprises the following steps: first, an initial dielectric layer is deposited on the regrown ring, on the sidewalls and top of the first type epitaxial layer. Then, the top of the initial dielectric layer is planarized to the top of the first type epitaxial layer, and a bottom contact is deposited on the first type epitaxial layer. Then, another dielectric layer is deposited on the initial dielectric layer and on the sidewalls and top of the mesa structure, and the dielectric layer covers the top contact to form a finished dielectric layer. Next, an opening is formed in the dielectric layer and exposes the bottom contact.

[0276] The opening is formed by a conventional plasma etching process, and the bottom contact 06 is formed by a conventional vapor deposition process.

[0277] In another embodiment, the bottom contact 06 can be formed before the deposition of the regrown layer 04. Then, the regrown layer 04 is deposited on the sidewalls of the light emitting layer 03, the sidewalls and top of the first type epitaxial layer 01, and the bottom contact 06. Next, the dielectric layer 05 is formed on the regrown layer 04. Finally, an opening is formed in the dielectric layer 05 and the regrown layer 04 to expose the bottom contact 06.

[0278] Referring to Figure 35 Step 5 comprises forming a bottom connection structure 07 in the opening.

[0279] Here, the material of the bottom connection structure 07 is deposited into the opening and on the bottom contact by a conventional vapor deposition process.

[0280] Referring to Figure 36 Step 6 comprises bonding the first type epitaxial layer 01 and the bottom connection structure 07 to the IC backplane 00 by inverting the semiconductor substrate 00'. Then, the semiconductor substrate 00' is removed.

[0281] Here, the semiconductor substrate 00' with the epitaxial structure is first inverted. Then, the bottom connection structure 07 is bonded to the pads of the IC backplane 00. After the bonding process, the semiconductor substrate 00' is removed by a conventional removal process such as a laser lift-off method.

[0282] Referring to Figure 37Step 7 includes forming the top contact 09 and the top conductive layer 08 on the second type epitaxial layer 02.

[0283] Here, the top contact 09 is deposited on top of the second type epitaxial layer 02, where other areas are protected with a mask, and the mask is removed afterwards. Then, the top conductive layer 08 is deposited on the second type epitaxial layer 02 by a conventional vapor deposition process.

[0284] Embodiment 4

[0285] The micro-LED panel of Embodiment 4 includes an array of micro-LED structures. Figure 38 is a cross-sectional structure diagram of a micro-LED panel according to some embodiments (e.g., Embodiment 4) of the present disclosure.

[0286] Referring to Figure 38 , the micro-LED structure includes: a mesa structure, a regrowth layer 04, a bottom contact 06, a bottom connection structure 07, an IC backplane 00, a top contact 09, and a top conductive layer 08.

[0287] The mesa structure consists of or includes, from bottom to top: a first type epitaxial layer 01, a light emitting layer 03, and a second type epitaxial layer 02. Here, the regrowth layer 04 is grown on the entire sidewall of the first type epitaxial layer 01, the entire sidewall of the light emitting layer 03, and the entire sidewall of the second type epitaxial layer 02. In addition, the regrowth layer 04 completely fills the space between adjacent mesa structures. In other words, the regrowth layer 04 also serves to isolate the sidewalls of the mesa structures from each other. The top width of the regrowth layer 04 is the same as the top width of the space between adjacent mesa structures.

[0288] In addition, the regrowth layer 04 is very thin, no more than 10 nm, such as 5 nm, so the regrowth layer 04 is transparent in some embodiments. The regrowth layer 04 is also formed at the bottom of the mesa structure. The bottom contact 06 and the bottom connection structure 07 are formed in the regrowth layer 04 underneath the mesa structure, and the bottom contact 06 and the bottom connection structure 07 are electrically connected to the first type epitaxial layer 01.

[0289] In addition, the top contact 09 and the top conductive layer 08 are formed on top of the second type epitaxial layer 02. In some embodiments, the top conductive layer 08 is formed continuously across the micro-LED panel in this embodiment. In another embodiment, referring to Figure 47 , the top conductive layer 08 is formed on the top contact and part of the top surface of the second type epitaxial layer 02.

[0290] The manufacturing method of the above micro-LED panel in this embodiment 4 includes the following steps.

[0291] Figures 39 to 46Fig. 1 illustrates a micro-LED panel according to some embodiments of the present disclosure (e.g., embodiment 1). Figure 38 Fig. 1 illustrates a micro-LED panel according to some embodiments of the present disclosure (e.g., embodiment 1).

[0292] Referring to Fig. 1, step 1 includes providing a semiconductor substrate 00’ having an epitaxial structure. Figure 39 Here, the epitaxial structure includes, from top to bottom, a first-type epitaxial layer 01, a light-emitting layer 03, and a second-type epitaxial layer 02. The material of the semiconductor substrate 00’ can be GaN, GaAs, etc., and the epitaxial structure is grown on the semiconductor substrate 00’.

[0293] Referring to Fig. 1, step 2 includes forming mesa structures by patterning the mesa structure from top to bottom.

[0294] Figure 40 Here, the epitaxial structure is etched from top to bottom by a conventional plasma etching process.

[0295] Referring to Fig. 1, step 3 includes forming a regrowth layer 04 that is completely filled in the space of adjacent mesa structures and on the top of the semiconductor substrate 00’.

[0296] Here, the regrowth layer 04 is regrown on the entire sidewall of the light-emitting layer 03, the first-type epitaxial layer 01, and the second-type epitaxial layer 02. In addition, the regrowth layer 04 is also formed on the top surface of the first-type epitaxial layer 01 and the exposed top surface of the semiconductor substrate 00’. In this regrowth process, the temperature is 400-1000 °C, and the regrowth time is 5-1000 seconds. The material used for the regrowth process is the same as that of the first-type epitaxial layer 01 and / or the second-type epitaxial layer 02, but without intentional doping ions. Figure 41 Referring to Fig. 1, step 4 includes forming an opening in the regrowth layer 04 on the first-type epitaxial layer 01, and referring to Fig. 1, step 5 includes forming a bottom contact 06 on the surface of the first-type epitaxial layer 01 in the opening.

[0297] Here, the opening is formed by a conventional plasma etching process, and the bottom contact 06 is formed by a conventional vapor deposition process.

[0298] Figure 42 In another embodiment, the bottom contact 06 can be formed before depositing the regrowth layer 04. Then, the regrowth layer 04 is deposited on the sidewall of the light-emitting layer 03, the sidewall and top of the first-type epitaxial layer 01, and the bottom contact 06. Finally, the opening is formed in the regrowth layer 04 to expose the bottom contact 06. Figure 43 Referring to Fig. 1, step 4 includes forming an opening in the regrowth layer 04 on the first-type epitaxial layer 01, and referring to Fig. 1, step 5 includes forming a bottom contact 06 on the surface of the first-type epitaxial layer 01 in the opening.

[0299]

[0300]

[0301] Referring to Fig. 1, step 4 includes forming an opening in the regrowth layer 04 on the first-type epitaxial layer 01, and referring to Fig. 1, step 5 includes forming a bottom contact 06 on the surface of the first-type epitaxial layer 01 in the opening. Figure 44 ​​​​Step 5 includes forming a bottom connection structure 07 in the opening.

[0302] Here, the material of the bottom connection structure 07 is deposited into the opening and on the bottom contact by a conventional vapor deposition process.

[0303] Referring to Figure 45 Step 6 includes bonding the bottom connection structure 07 with the IC backplane 00 by inverting the semiconductor substrate 00’. Then, the semiconductor substrate 00’ is removed.

[0304] Here, the semiconductor substrate 00’ with the epitaxial structure is first inverted. Then, the bottom connection structure 07 is bonded with the pads of the IC backplane 00. After the bonding process, the semiconductor substrate 00’ is removed by a conventional removal process such as a laser lift-off method.

[0305] Referring to Figure 46 Step 7 includes forming a top contact 09 and a top conductive layer 08 on the second type epitaxial layer 02.

[0306] Here, the top contact 09 is deposited on top of the second type epitaxial layer 02, where other areas are protected with a mask, which is removed after the top contact 09 is formed. Then, the top conductive layer 08 is deposited on the second type epitaxial layer 02 by a conventional vapor deposition process.

[0307] Embodiment 5

[0308] The micro-LED panel of embodiment 5 includes an array of micro-LED structures. Figure 47 is a cross-sectional structure diagram of a micro-LED panel according to some embodiments (e.g., embodiment 5) of the present disclosure.

[0309] Referring to Figure 47 The micro-LED structure includes: a mesa structure, a regrowth layer 04, a bottom contact 06, a bottom connection structure 07, an IC backplane 00, a top contact 09, and a top conductive layer 08.

[0310] The mesa structure includes, from bottom to top: a first type epitaxial layer 01, a light emitting layer 03, and a second type epitaxial layer 02. Here, the regrowth layer 04 is grown on the entire sidewall of the first type epitaxial layer 01, the entire sidewall of the light emitting layer 03, and the entire sidewall of the second type epitaxial layer 02. In addition, the regrowth layer 04 completely fills in the space between adjacent mesa structures. The top width of the regrowth layer 04 is the same as the top width of the space between adjacent mesa structures.

[0311] Furthermore, the regrowth layer 04 is very thin, no more than 10 nm, such as 5 nm, so in some embodiments the regrowth layer 04 is transparent. A dielectric layer 05 is also formed at the bottom of the mesa structure and the bottom of the regrowth layer 04. A bottom connection structure 07 is formed in the dielectric layer 05 and electrically connected to the first type epitaxial layer 01. Preferably, the material of the dielectric layer 05 is one or more of SiO2, SiNx, Al2O3, AlN, HfO2, TiO2, and / or ZrO2, etc. In addition, in some embodiments, the material of the dielectric layer 05 is transparent.

[0312] In addition, a top contact 09 and a top conductive layer 08 are formed on the top of the second type epitaxial layer. In some embodiments, here, the top conductive layer 08 is formed on the top contact and part of the top surface of the second type epitaxial layer 02.

[0313] The manufacturing method of the micro-LED panel in the above embodiment 5 includes the following steps.

[0314] Figures 48 to 55 Fig. 1 illustrates the steps of the manufacturing method of the micro-LED panel in Figure 47 Fig. 1 illustrates the steps of the manufacturing method of the micro-LED panel in

[0315] Referring to Figure 48 , step 1 includes providing a semiconductor substrate 00’ with an epitaxial structure; and the epitaxial structure includes, from top to bottom, a first type epitaxial layer 01, a light emitting layer 03, and a second type epitaxial layer 02.

[0316] Here, the epitaxial structure includes, from top to bottom, a first type epitaxial layer 01, a light emitting layer 03, and a second type epitaxial layer 02. The material of the semiconductor substrate 00’ can be GaN, GaAs, etc., and the epitaxial structure is grown on the semiconductor substrate 00’.

[0317] Referring to Figure 49 , step 2 includes forming a mesa structure by patterning the epitaxial structure from top to bottom.

[0318] Here, the epitaxial structure is etched from top to bottom by a conventional plasma etching process.

[0319] Referring to Figure 50 , step 3 includes forming a regrowth layer 04 by an epitaxial material regrowth process, which completely fills in the space between adjacent mesa structures and on the entire sidewall of the epitaxial structure.

[0320] Here, the regrowth layer 04 is regrown on the entire sidewalls of the light emitting layer 03, the first type epitaxial layer 01 and the second type epitaxial layer 02. In addition, the regrowth layer 04 is also formed on the top surface of the first type epitaxial layer 01 and the exposed top surface of the semiconductor substrate 00'. Then, the regrowth layer 04 is etched, which stops on the top of the mesa structure, exposing the top of the mesa structure.

[0321] In this regrowth process, the temperature is 400°C to 1000°C, and the regrowth time is 5 seconds to 1000 seconds. The material used for the regrowth process is the same as the material of the first type epitaxial layer 01 and / or the material of the second type epitaxial layer 02, but without intentional doping ions.

[0322] Referring to Figure 51 , step 4 includes forming a dielectric layer 05 on the top of the first type epitaxial layer 01 and the top of the regrowth layer 04.

[0323] Here, the dielectric layer 05 is deposited on the top of the first type epitaxial layer 01 and the top of the regrowth layer 04 by a conventional chemical vapor deposition process.

[0324] Referring to Figure 52 , step 5 includes forming an opening in the dielectric layer 05 on the first type epitaxial layer 01, and forming a bottom contact 06 on the surface of the first type epitaxial layer 01 in the opening.

[0325] Here, the opening is formed by a conventional plasma etching process, and the bottom contact 06 is formed by a conventional vapor deposition process.

[0326] In another embodiment, the bottom contact can be formed before depositing the regrowth layer. Then, the regrowth layer is deposited on the sidewalls of the light emitting layer, the sidewalls and the top of the first type epitaxial layer, and the bottom contact. Next, the dielectric layer is formed on the regrowth layer. Finally, the opening is formed in the dielectric layer and the regrowth layer to expose the bottom contact.

[0327] Referring to Figure 53 , step 6 includes forming a bottom connection structure 07 in the opening.

[0328] Here, the material of the bottom connection structure 07 is deposited into the opening and on the bottom contact 06 by a conventional vapor deposition process.

[0329] Referring to Figure 54 , step 7 includes bonding the bottom connection structure 07 with the IC backplane 00 by inverting the semiconductor substrate 00'. Then, the semiconductor substrate 00' is removed.

[0330] Here, the semiconductor substrate 00' having the epitaxial structure is first inverted. Then, the bottom connection structure 07 is bonded with the pads of the IC backplane 00. After the bonding process, the semiconductor substrate 00' is removed by a conventional removal process such as a laser lift-off method.

[0331] Referring to Figure 55 , step 8 includes forming the top contact 09 and the top conductive layer 08 on top of the second type epitaxial layer 02.

[0332] Here, the top contact 09 is deposited on top of the second type epitaxial layer 02, wherein other areas are protected with a mask, and the mask is removed after the formation of the top contact 09. Then, the top conductive layer 08 is formed on top of the second type epitaxial layer 02 and on top of and sidewalls of the top contact 09, other areas are protected with another mask, and the another mask is removed after the formation of the top conductive layer 08. In addition, the top conductive layer 08 is formed on part of the top surface of the second type epitaxial layer 02 without covering the entire second type epitaxial layer 02. The top contact 09 and the top conductive layer 08 are formed by a conventional vapor deposition process.

[0333] It should be understood by those skilled in the art that the micro display panel is not limited by the above structure, and can include more or fewer components than those illustrated, or can combine some components, or can use different components.

[0334] It should be understood by those skilled in the art that all or part of the steps for implementing the foregoing embodiments can be implemented by hardware, or can be implemented by a program instructing related hardware. The program can be stored in a flash memory, a conventional computer device, a central processing module, an adjustment module, etc.

[0335] The above description is merely an embodiment of the present disclosure, and the present disclosure is not limited thereto. Modifications, equivalent replacements and improvements made without departing from the concepts and principles of the present disclosure will fall within the scope of protection of the present disclosure.

[0336] Other embodiments also include various subsets of the above-described embodiments of the embodiments shown in Figures 1 to 55 assembled or otherwise rearranged in various other embodiments.

[0337] While the description contains many specifics, these should not be construed as limitations on the scope of the application, but merely as illustrations of different examples and aspects of the application. It is appreciated that the scope of the application encompasses other embodiments not discussed in detail above. For example, the above-described methods can be applied to the integration of functional devices other than LEDs and OLEDs with control circuitry other than pixel drivers. Examples of non-LED devices include vertical cavity surface emitting lasers (VCSELs), photodetectors, microelectromechanical systems (MEMS), silicon photonics devices, power electronics devices, and distributed feedback lasers (DFB). Examples of other control circuitry include current drivers, voltage drivers, transimpedance amplifiers, and logic circuits.

[0338] The foregoing description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the embodiments described herein and variants thereof. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the subject matter disclosed herein. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0339] Features of the present application can be realized by or with the aid of a computer program product, such as a storage medium (a plurality of media) or a computer readable storage medium (a plurality of media) having store therein or thereon instructions which can be used to program a processing system to perform any of the features presented herein. The storage medium can include, without limitation, high-speed random access memory such as DRAM, SRAM, DDR RAM or other random access solid state memory devices; and can include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. The instructions can optionally be compressed or encrypted. The storage medium can optionally be located in a different location from the processing system, such as a server or a cloud storage device. The storage medium can be coupled to the processing system by a wired or wireless connection.

[0340] Features of the present application stored on any machine readable medium (a plurality of media) can comprise, take the form of, include, or be a part of software and / or firmware for controlling hardware of a processing system and enabling the processing system to interact with other mechanisms using results of the present application. Such software or firmware can include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0341] It should be understood that, although the terms “first,” “second,” etc. can be used herein to describe various elements or steps, these elements or steps should not be limited by these terms. These terms are only used to distinguish one element or step from another.

[0342] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the claims. As used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0343] As used herein, the term "if' can be construed to mean "when" or "upon" or "in response to determining" the stated condition is true, according to context. Similarly, the phrase "if it is determined" or "if [a stated condition is true]" or "when [a stated condition is true]" can be construed to mean "when" or "upon" or "in response to determining," according to context, that the stated condition is true.

[0344] The foregoing description of the embodiments has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the claims to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the application and its practical application to thereby enable others skilled in the art to best utilize the application and various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. A micro-LED panel having an array of micro-LED structures, comprising a plurality of micro-LED structures, wherein each of the plurality of micro-LED structures comprises: a mesa structure comprising, from bottom to top: a first type of epitaxial layer, a light emitting layer, and a second type of epitaxial layer; and a regrowth layer grown on a portion of sidewalls of the first type of epitaxial layer, an entire sidewall of the light emitting layer, and a portion of sidewalls of the second type of epitaxial layer, wherein a dielectric layer is formed between adjacent mesa structures of the plurality of micro-LED structures; and a top end of the regrowth layer further protrudes into the dielectric layer and connects between adjacent mesa structures of the plurality of micro-LED structures.

2. The micro-LED panel of claim 1, wherein the regrowth layer on the sidewall of the light emitting layer is not parallel to an extension direction of the light emitting layer.

3. The micro-LED panel of claim 1, wherein an inclination angle of the regrowth layer on the sidewall of the light emitting layer with respect to an extension direction of the light emitting layer is 30 degrees to 90 degrees; and the regrowth layer protruding into the dielectric layer is parallel to a bottom surface of the second type of epitaxial layer.

4. The micro-LED panel of claim 1, wherein an inclination angle of the regrowth layer on the sidewall of the light emitting layer with respect to an extension direction of the light emitting layer is 30 degrees to 90 degrees; and the regrowth layer protruding along the dielectric layer is parallel to a top surface of the dielectric layer.

5. The micro-LED panel of claim 1, wherein a diameter of the mesa structure is less than or equal to 3 microns.

6. The micro-LED panel of claim 1, wherein: the light emitting layer comprises a top surface, an edge surface, and a bottom surface; the regrowth layer is grown on the edge surface of the light emitting layer; and the regrowth layer is not grown on the top surface and the bottom surface of the light emitting layer.

7. The micro-LED panel of claim 1, wherein: the light emitting layer comprises a plurality of pairs of quantum wells; and the regrowth layer on the sidewall of the light emitting layer is not parallel to a surface of each of the plurality of pairs of quantum wells.

8. The micro-LED panel of claim 1, wherein a cross-section of the light emitting layer has a straight line shape without any bending.

9. The micro-LED panel of claim 1, wherein: a material of the regrowth layer having intrinsic dopant ions is the same as a material of the first type of epitaxial layer or a material of the second type of epitaxial layer; and the material of the regrowth layer does not include extrinsic dopant ions.

10. The micro-LED panel of claim 1, wherein the material of the regrowth layer is one or more of GaP, AlP, GaAs, InP, AlInP, GaInP, AIN, GaN, and / or InN.

11. The micro-LED panel of claim 1, wherein: the material of the regrowth layer is single crystalline; the material of the first type of epitaxial layer is single crystalline; and the material of the second type of epitaxial layer is single crystalline. ​ 12. The micro-LED panel of claim 1, wherein a bandgap of the regrowth layer is greater than a bandgap of the light emitting layer.

13. The micro-LED panel of claim 1, wherein a thickness of the regrowth layer is less than a thickness of the light emitting layer; and the thickness of the regrowth layer is less than or equal to 100 nm.

14. The micro-LED panel of claim 1, wherein: a resistance of the regrowth layer is higher than a resistance of the light emitting layer; and the regrowth layer is non-conductive.

15. The micro-LED panel of claim 1, wherein the dielectric layer is formed on a surface of the regrowth layer between adjacent mesa structures of the plurality of micro-LED structures.

16. The micro-LED panel of claim 1, wherein a material of the dielectric layer is one or more of SiO2, SiNx, Al2O3, AIN, HfO2, TiO2, and / or ZrO2.

17. The micro-LED panel of claim 1, wherein: a material of the first type epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and / or AlGalnP; and a material of the second type epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and / or AlGalnP.

18. The micro-LED panel of claim 1, wherein: a top contact is formed on top of the second type epitaxial layer; a top conductive layer is formed on top of the top contact; and the top conductive layer covers an entire top surface of the second type epitaxial layer and is formed continuously on an entire top surface of the micro-LED panel.

19. The micro-LED panel of claim 1, wherein: a top contact is formed on top of the second type epitaxial layer; a top conductive layer is formed on top of the top contact; and the top conductive layer covers a portion of a top surface of the second type epitaxial layer.

20. The micro-LED panel of claim 1, wherein: a bottom contact is formed on a bottom surface of the first type epitaxial layer; a bottom connection structure is formed on a bottom of the bottom contact configured to be bonded with an IC backplane.

21. The micro-LED panel of claim 1, wherein a bottom connection structure is formed in the dielectric layer.

22. The micro-LED panel of claim 1, wherein a top contact is formed on and electrically connected to a top of the mesa structure.

23. A method of manufacturing a micro-LED panel, comprising: providing a semiconductor substrate having an epitaxial structure, wherein the epitaxial structure comprises, from top to bottom, a first type epitaxial layer, a light emitting layer, and a second type epitaxial layer; forming a plurality of mesa structures by patterning the epitaxial structure; forming a first mask pattern on the semiconductor substrate to cover sidewalls of the first type epitaxial layer, sidewalls of the light emitting layer, and a portion of sidewalls of the second type epitaxial layer; depositing a first dielectric layer on the substrate between adjacent mesa structures of the plurality of mesa structures, a top of the first dielectric layer being lower than a bottom of the light emitting layer; removing the first mask pattern; forming a regrowth layer on an entire sidewall of the light emitting layer, on a portion of a sidewall of the second type epitaxial layer, and on a portion of a sidewall of the first type epitaxial layer by an epitaxial material regrowth process; forming a bottom contact in the regrowth layer on a top surface of the first type epitaxial layer and forming a second dielectric layer on the regrowth layer having an opening exposing a top of the bottom contact; forming a bottom connection structure in the opening; bonding the bottom connection structure with an IC backplane, inverting the semiconductor substrate, and removing the semiconductor substrate; and forming a top contact and a top conductive layer on the second type epitaxial layer.

24. A method of manufacturing a micro-LED panel according to claim 23, wherein, In the regrowth process, a regrowth temperature is 400°C to 1000°C and a regrowth time is 5 seconds to 1000 seconds.

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