Patent Application
20250113667
The present disclosure generally relates to light emitting diode (LED) technology and, more particularly, to a micro LED panel and a method of manufacturing the micro LED structure.
Display technologies are becoming increasingly important in today's commercial electronic devices. These display panels are widely used in stationary large screens such as liquid crystal display 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.
Inorganic micro light emitting diodes are of increasing importance because of their use in various applications including self-emissive micro-displays, visible light communications and opto-genetics. The micro LEDs show higher output performance than conventional LEDs due to better strain relaxation, improved light extraction efficiency, and uniform current spreading. The micro LEDs also exhibit improved thermal effects, and operate at a higher current density, fast response rate, larger work temperature range, higher resolution, color gamut, and contrast and lower power consumption as compared with conventional LEDs.
To achieve higher pixel density, the size of the micro LEDs is reduced to less than 200 nm. However, the efficiency and the carrier lifetime of the micro LED array based device degrade drastically with the reduced micro LED size to a large extent, by surface recombination and poor p-type conduction induced by top-down etching. The performance of micro LEDs also suffers severely from quantum-confined stark effect, particularly due to the strain-induced polarization field, which leads to unstable operation, and significant variations in emission wavelengths with increasing current. Additionally, with the decrease of the micro LED diameter, 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 the non-radiation recombination at the surface of the micro LED structures.
Additionally, the emission of the conventional micro LED structure is mainly distributed at any direction which exhibits poor directional emission and reduces the light intensity along the vertical direction. To realize the directional emission of the micro LED structure, extra reflective structures are configured around the mesa of the micro LED structure and at the bottom of the mesa, so as to reflect the emission light to a same direction, which causes a complex manufacturing process and increases the cost of the micro LED.
Furthermore, in the micro LED array based device, one micro LED is conventionally used as one pixel such as in monolithic micro LED array panel. However, the micro LED structure with smaller diameter shows lower external quantum efficiency (EQE), which reduces the light efficiency of each pixel.
The above content is only used to assist in understanding the technical solutions of the present application, and does not constitute an admission that the above is prior art.
There is a need for improved display designs that improve upon, and help to address the shortcomings of conventional display systems, such as those described above. In particular, there is a need for display panels with improved efficiency with better images.
In order to overcome the drawback mentioned above, the present invention provides a micro LED panel, to improve the light emitting efficiency, to avoid crosstalk, to minimize the surface carrier loss, and to optimize the quantum well sidewall area.
To achieve the above objectives, some exemplary embodiments of the present disclosure provide a micro LED panel having a micro LED structure array, comprising:
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, a dielectric layer is formed between the adjacent mesa structures; and the top end of the re-growth layer further extrudes into the dielectric layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer extruded into the dielectric layer is connected to an adjacent light emitting layer and an adjacent first type epitaxial layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer is grown on the whole sidewall of the first type epitaxial layer, and the whole sidewall of the light emitting layer and part of the first type epitaxial layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer is grown on the part of the sidewall of the first type epitaxial layer, the whole sidewall of the light emitting layer and the part of sidewall of the second type epitaxial layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer on the sidewall of the light emitting layer is not parallel to an extending direction of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, an inclined angle of the re-growth layer on the sidewall of the light emitting layer is 30 degrees to 90 degrees relative to the extending direction of the light emitting layer; and the re-growth layer extruded into the dielectric layer is parallel to bottom surface of the second type epitaxial layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, diameter of the mesa structure is not more than 3 μm.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the light emitting layer comprises a top surface, an edge surface and a bottom surface, and the re-growth layer is grown on the edge surface of the light emitting layer and not grown on the top surface and the bottom surface of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the light emitting layer comprises a plurality of pairs of quantum wells; and the re-growth layer on the sidewall of the light emitting layer is not parallel to surface of each of the plurality of pairs of quantum wells.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the light emitting layer has a straight line shape without any bending.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the re-growth layer with intrinsic doped ions is the same as material of the first type epitaxial layer and/or material of the second type epitaxial layer but without intentional doping ions.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the re-growth layer is one or more of GaP, AlP, GaAs, InP, AlInP, GaInP, AlN, GaN, and/or InN.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the re-growth layer is monocrystal, material of the first epitaxial layer is monocrystal and material of the second epitaxial layer is monocrystal.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, a band gap of the re-growth layer is greater than a band gap of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, thickness of the re-growth layer is less than thickness of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the thickness of the re-growth layer is not more than 100 nm.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, resistance of the re-growth layer is higher than resistance of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer is not electrically conductive.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the dielectric layer is formed on surface of the re-growth layer between adjacent mesa structures.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the dielectric layer is one or more of SiO2, SiNx, Al203, AlN, HfO2, TiO2, and/or ZrO2.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the first type epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and/or AlGaInP, and material of the second epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and/or AlGaInP.
Some exemplary embodiments of the present disclosure provide a method of manufacturing the micro LED panel, comprising:
In some exemplary embodiments or any combination of exemplary embodiments, the method of manufacturing the micro-LED panel further includes: in step 6, before forming the re-growth layer, forming a second mask pattern covering top and part of the sidewall of the first type epitaxial layer, wherein the re-growth layer is formed at the whole sidewall of the light emitting layer, the at least part of the sidewall of the first type epitaxial layer and on the part of the sidewall of the second type epitaxial layer, and after forming the re-growth layer, removing the second mask pattern.
In some exemplary embodiments or any combination of exemplary embodiments of the method of manufacturing the micro-LED panel, in step 6, the re-growth layer is directly formed on the whole sidewall of the light emitting layer, on whole sidewall of the first type epitaxial layer, and on top of the first type epitaxial layer.
In some exemplary embodiments or any combination of exemplary embodiments of the method of manufacturing the micro-LED panel, in step 6, temperature in the re-growth process is 400° C. to 1000° C., and re-growth time is 5 seconds to 1000 seconds.
Some exemplary embodiments of the present disclosure provide a micro LED panel having a micro LED structure array, comprising:
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, a dielectric layer is formed between adjacent micro LED structures; and the top end of the re-growth layer further extrudes along the top surface of the dielectric layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer on the sidewall of the light emitting layer is not parallel to an extending direction of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, an inclined angle of the re-growth layer on the sidewall of the light emitting layer is 30 degrees to 90 degrees relative to the extending direction of the light emitting layer; and the re-growth layer extruded along the dielectric layer is parallel to the top surface of the dielectric layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer extruded along the top of the dielectric layer is connected to an adjacent light emitting layer and the second type epitaxial layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, diameter of the mesa structure is not more than 3 μm.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the light emitting layer comprises a top surface, an edge surface and a bottom surface, and the re-growth layer is grown on the edge surface of the light emitting layer and not grown on the top surface and the bottom surface of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the light emitting layer comprises a plurality of pairs of quantum wells; the re-growth layer on the sidewall of the light emitting layer is not parallel to each of the plurality of pairs of quantum wells.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the light emitting layer has a straight line shape without any bending.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the re-growth layer with intrinsic doped ions is the same as material of the first type epitaxial layer and/or material of the second type epitaxial layer but without intentional doping ions.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the re-growth layer is one or more of GaP, AlP, GaAs, InP, AlInP, GaInP, AlN, GaN, and/or InN.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the re-growth layer is monocrystal, material of the first epitaxial layer is monocrystal and material of the second epitaxial layer is monocrystal.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, a band gap of the re-growth layer is greater than a band gap of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, thickness of the re-growth layer is less than thickness of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, thickness of the re-growth layer is not more than 100 nm.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, resistance of the re-growth layer is higher than resistance of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer is not electrically conductive.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, a dielectric layer is further formed on surface of the re-growth layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the dielectric layer is one or more of SiO2, SiNx, Al2O3, AlN, HfO2, TiO2, and/or ZrO2.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the first type epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and/or AlGaInP, and material of the second type epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and/or AlGaInP.
Some exemplary embodiments of the present disclosure provide a method of manufacturing the micro LED panel, comprising:
In some exemplary embodiments or any combination of exemplary embodiments of the method of manufacturing the micro-LED panel, in step 4, the re-growth layer is further formed on the substrate between adjacent mesa structures; and temperature in the re-growth process is 400° C. to 1000° C., and re-growth time is 5 seconds to 1000 seconds.
Some exemplary embodiments of the present disclosure provide a micro LED panel including a micro LED structure array, comprising:
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, a dielectric layer is formed between adjacent mesa structures.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, top end of the re-growth layer further extrudes along the top surface of the dielectric layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer on the sidewall of the light emitting layer is not parallel to an extending direction of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, an inclined angle of the re-growth layer on the sidewall of the light emitting layer is 30 degrees to 90 degrees relative to the extending direction of the light emitting layer; and, the re-growth layer extruded along the dielectric layer is parallel to top surface of the dielectric layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer extruded along the top of the dielectric layer is connected to an adjacent second type epitaxial layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer is further formed on whole sidewall of the mesa structure.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer is further formed on bottom surface of the first type epitaxial layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, diameter of the mesa structure is not more than 3 μm.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the light emitting layer comprises a top surface, an edge surface and a bottom surface, and the re-growth layer is grown on the edge surface of the light emitting layer and not grown on the top surface and the bottom surface of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the light emitting layer comprises a plurality of pairs of quantum wells; and the re-growth layer on the sidewall of the light emitting layer is not parallel to surface of each of the plurality of pairs of quantum wells.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the light emitting layer has a straight line shape without any bending.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the re-growth layer with intrinsic doped ions is the same as material of the first type epitaxial layer and/or material of the second type epitaxial layer but without intentional doping ions.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the re-growth layer is one or more of GaP, AlP, GaAs, InP, AlInP, GaInP, AlN, GaN, and/or InN.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the re-growth layer is monocrystal, material of the first epitaxial layer is monocrystal and material of the second epitaxial layer is monocrystal.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, a band gap of the re-growth layer is greater than a band gap of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, thickness of the re-growth layer is less than thickness of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the thickness of the re-growth layer is not more than 100 nm.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, resistance of the re-growth layer is higher than resistance of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer is not electrically conductive.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the dielectric layer is further formed at bottom of the mesa structure; and the material of the dielectric layer is one or more of SiO2, SiNx, Al2O3, AlN, HfO2, TiO2, and/or ZrO2.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, a bottom connected structure is formed in the dielectric layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the first type epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and/or AlGaInP, and material of the second type epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and/or AlGaInP.
Some exemplary embodiments of the present disclosure provide a method of manufacturing the micro LED panel, comprising:
In some exemplary embodiments or any combination of exemplary embodiments of the method of manufacturing the micro-LED panel, in step 3, the re-growth layer is further formed on whole sidewall and top of the first type epitaxial layer and on top of the semiconductor substrate; in step 4, the opening is further formed in the re-growth layer on the first type epitaxial layer; and, temperature in the re-growth process is 400° C. to 1000° C., and re-growth time is 5 seconds to 1000 seconds.
In some exemplary embodiments or any combination of exemplary embodiments, the method of manufacturing the micro-LED panel further includes: in step 3, before forming the re-growth layer, forming a mask pattern covering top and part of the sidewall of the first type epitaxial layer; and after forming the re-growth layer, removing the mask pattern.
In some exemplary embodiments or any combination of exemplary embodiments, the method of manufacturing the micro-LED panel further includes: in step 3, before forming the re-growth layer, forming a mask pattern covering part of the sidewall of the second type epitaxial layer; and after forming the re-growth layer, removing the mask pattern.
In some exemplary embodiments or any combination of exemplary embodiments, the method of manufacturing the micro-LED panel further includes: in step 3, before forming the re-growth layer, forming a first mask pattern covering 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 re-growth layer, removing the first mask pattern and the second mask pattern.
Some exemplary embodiments of the present disclosure provide a micro LED panel, including a micro LED structure array, comprising:
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, top width of the re-growth layer is the same as top width of space between the adjacent mesa structures.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, diameter of the mesa structure is not more than 3 μm.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the light emitting layer comprises a top surface, an edge surface and a bottom surface, and the re-growth layer is grown on the edge surface of the light emitting layer and not grown on the top surface and the bottom surface of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the light emitting layer comprises a plurality of pairs of quantum wells.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the light emitting layer has a straight line shape without any bending.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the re-growth layer with intrinsic doped ions is the same as material of the first type epitaxial layer and/or material of the second type epitaxial layer but without intentional doping ions.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the re-growth layer is one or more of GaP, AlP, GaAs, InP, AlInP, GaInP, AlN, GaN, and/or InN.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the re-growth layer is monocrystal, material of the first epitaxial layer is monocrystal and material of the second epitaxial layer is monocrystal.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, a band gap of the re-growth layer is greater than a band gap of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, thickness of the re-growth layer is less than thickness of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the thickness of the re-growth layer is not more than 100 nm.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, resistance of the re-growth layer is higher than resistance of the light emitting layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer is not electrically conductive.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, material of the first type epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and/or AlGaInP, and material of the second type epitaxial layer is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, and/or AlGaInP.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, the re-growth layer is further formed at bottom of the mesa structure; and a bottom connected structure is formed in the re-growth layer and electrically connected to the first type epitaxial layer.
In some exemplary embodiments or any combination of exemplary embodiments of the micro-LED panel, a dielectric layer is further formed at the bottom of the mesa structure and bottom of the re-growth layer; and a bottom connected structure is formed in the dielectric layer and electrically connected to the first type epitaxial layer.
Some exemplary embodiments of the present disclosure provide a method of manufacturing the micro LED panel, comprising:
In some exemplary embodiments or any combination of exemplary embodiments of the method of manufacturing the micro-LED panel, in step 3, temperature in the re-growth process is 400° C. to 1000° C., and re-growth time is 5 seconds to 1000 seconds.
Some exemplary embodiments of the present disclosure provide a method of manufacturing the micro LED panel, comprising:
In some exemplary embodiments or any combination of exemplary embodiments of the method of manufacturing the micro-LED panel, in step 3, temperature in the re-growth process is 400° C. to 1000° C., and re-growth time is 5 seconds to 1000 seconds.
The micro LED panel provided by the present disclosure can avoid the nonradiative recombination at the sidewalls of the micro LED structure. Furthermore, compared with the conventional micro LEDs, the micro LED structure of the present disclosure has a high directional emission, with no other reflective structure, thereby simplifying the micro LED structure and decreasing the cost. Furthermore, the present disclosure can also inhibit the non-radiation recombination at the surface of the micro LED structures, thereby improving the image quality and increase the EQE of the pixels.
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 may not have been selected to delineate or circumscribe the inventive subject matter.
So that the present disclosure can be understood in greater detail, a more particular description may be had by reference to the features of various embodiments, some of which are illustrated in the appended drawings. The appended drawings, however, merely illustrate pertinent features of the present disclosure and are therefore not to be considered limiting, for the description may admit to other effective features.
For convenience, “up” is used to mean away from the substrate of a light emitting structure as shown in the Figures, “down” means toward the substrate, and other directional terms such as top, bottom, above, below, under, beneath, etc. are interpreted accordingly.
In accordance with common practice, the various features illustrated in the drawings may not be drawn to scale. Accordingly, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may not depict all of the components of a given system, method or device. Finally, like reference numerals may be used to denote like features throughout the specification and figures.
Numerous details are described herein in order to provide a thorough understanding of the example embodiments illustrated in the accompanying drawings. However, some embodiments may be practiced without many of the specific details, and the scope of the claims is only limited by those features and aspects specifically recited in the claims. Furthermore, well-known processes, components, and materials have not been described in exhaustive detail so as not to unnecessarily obscure pertinent aspects of the embodiments described herein.
As discussed above, to resolve the problem in the related technologies, in some embodiments, a micro LED panel comprising multiple micro LED structures is disclosed in the present disclosure. The dimension of the micro LED panel is not more than 1 cm. The micro LED structures are formed in the micro LED panel in an array, with a resolution such as 720*480, 640*480, 1920*1080, 1280*720, 2 k, or 4 k. The diameter of the micro LED structure is at a nano-meter level, such as 20 nm to 100 nm.
In some embodiments, the light emitting layer 03 is formed by multiple pairs of quantum well layers. The material of the quantum well layer can be one of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, AlGaInP etc. Additionally, the thickness of the first type epitaxial layer 01 is larger than the thickness of the second type epitaxial layer 02 and the thickness of the light emitting layer 03 is less than that of the first type epitaxial layer 01. Preferably, the thickness of the first type epitaxial layer 01 is 700 nm˜2 μm, the thickness of the second type epitaxial layer 02 is 100˜200 nm. Preferably, the thickness of a single quantum well layer is not more than 30 nm. In some examples, the light emitting layer 03 includes not more than three pairs of quantum well layers.
In some embodiments, the first type epitaxial layer 01 may have multiple stacked first type epitaxial sub-layers, the second type epitaxial layer 02 may have multiple stacked second type epitaxial sub-layers. For example, the top layer of the first type epitaxial sub-layer is a P cap layer connected to the bottom of the light emitting layer 03, the bottom layer of the second type epitaxial sub-layer is an N cap layer connected to the top of the light emitting layer 03, for protecting the quantum well layers from being damaged.
Furthermore, the first type epitaxial layer 01 comprises one or more reflective mirror layers 011 (not shown in
In some embodiments, the top contact 09 is formed at the top surface of the second type epitaxial layer 02. The conductive type of the top contact 09 is the same as that of the second type epitaxial layer 02, such as, the second type is n type, the top contact 09 is n type top contact; or, the second type is p type, the top contact 09 is p type top contact. In some embodiments, the top contact 09 is made by metal or metal alloy, such as, AuGe, AuGeNi, etc. The top contact 09 is used for forming ohmic contact between the top conductive layer 08 and the second type epitaxial layer 02, so as to optimize the electrical property of the micro LEDs. The diameter of the top contact 09 is about 20 nm to 50 nm and the thickness of the top contact 09 is about 10 nm to 20 nm. In some embodiments, the top conductive layer 08 is transparent and electrically conductive, such as Indium Tin Oxide (ITO), Fluorine-doped Tin Oxide (FTO), etc.
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 that 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. Furthermore, since the light emits upward or downward from the LED mesa structure consisting or comprising of the first type epitaxial layer 01, the second type epitaxial layer 02 and the light emitting layer 03, so 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, therefore, the top contact 09 is also as a dot on the top surface of the second type epitaxial layer 02. For example, the width of the top contact 09 is less than ⅕, ⅙, 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 connected structure 07 is formed at the bottom of the bottom contact 06. The bottom connected structure 07 is used for connecting with the bottom electrode such as the contact pad in an IC backplane. Furthermore, the diameter of the bottom connected structure 07 is 20 nm to 1 μm. Preferably, the diameter of the bottom connected structure 07 is 800 n to 1 μm. Furthermore, 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 connected structure 07 are transparent conductive material, such as ITO, or FTO, etc. Additionally, in some embodiments, the material of the bottom contact 06 and the bottom connected structure 07 are not transparent. The material of the bottom contact 06 and the bottom connected structure 07 can be conductive metal. Preferably, the material of the bottom contact 06 can be selected from at least one of Au, Zn, Be, Cr, Ni, Ti, Ag and Pt. The material of the bottom connected structure 07 can be selected from at least one of Au, Zn, Be, Cr, Ni, Ti, Ag and Pt.
As shown in
In some embodiments, to avoid the surface carrier loss and the non-radiative recombination at the sidewall of the mesa structure, a re-growth layer 04 by a re-growth process is formed on the sidewall of the light emitting layer 03, even on the sidewall of the first type epitaxial layer 01 and on the sidewall of the second type epitaxial layer 02. For example, the re-growth layer can be grown on part of the sidewall of the light emitting layer 03 or on the whole sidewall of the light emitting layer. “Whole” means a substantial or entire portion. Furthermore, the re-growth layer 04 can be further formed on part of the first type epitaxial layer 01 or the whole sidewall of the first type epitaxial layer 01; and/or, the re-growth layer 04 can be further formed on part of the second type epitaxial layer 02 or the whole sidewall of the second type epitaxial layer 02.
In some embodiments, the re-growth layer 04 is grown on at least part of the sidewall of the first type epitaxial layer 01, the whole 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 re-growth layer 04 is grown on the whole sidewall of the first type epitaxial layer 01, the whole sidewall of the light emitting layer 03 and the whole sidewall of the second type epitaxial layer 02. In another embodiment, the re-growth layer 04 is grown on part of the sidewall of the first type epitaxial layer 01, the whole sidewall of the light emitting layer 03 and the whole sidewall of the second type epitaxial layer 02. In some embodiments, the re-growth layer 04 is grown on the whole sidewall of the first type epitaxial layer 01, the whole sidewall of the light emitting layer 03 and part of the sidewall of the second type epitaxial layer 02. In another embodiment, the re-growth layer 04 is grown on part of the sidewall of the first type epitaxial layer 01, the whole sidewall of the light emitting layer 03 and part of the sidewall of the second type epitaxial layer 02.
The re-growth layer 04 on the sidewall of the light emitting layer 03 is not parallel to the extending horizontal direction of the light emitting layer 03 as shown in
Herein, the material of the re-growth layer 04 with intrinsic doped ions 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 extrinsic doping ions. For example, when the materials of first type epitaxial layer 01 and the second type epitaxial layer 02 are the same, and the intentional ion doping levels for the material of first type epitaxial layer 01 and the material of the second type epitaxial layer 02 are different, the material of the re-growth layer 04 may be the same as the underlying first type epitaxial layer 01 and the material of the second type epitaxial layer 02 but without the intentional extrinsic doping ions. In another example, when the material of first type epitaxial layer 01 and the second type epitaxial layer 02 are not the same, and the intentional ion doping levels for the material of first type epitaxial layer 01 and the material of the second type epitaxial layer 02 are different, the material of the re-growth layer 04 may be the same as the first type epitaxial layer 01 or the material of the second type epitaxial layer 02 but without the intentional extrinsic doping ions. The light emitting layer is an active region of a PN-junction formed by the first type epitaxial layer 01 and the second type epitaxial layer 02, and can be considered as composed of the 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 re-growth layer that covers the first type epitaxial layer 01 is the same as the underlying first type epitaxial layer 01 but without the extrinsic intentional doping of the first type epitaxial layer 01, and the portion of the material of the re-growth layer that covers the second type epitaxial layer 02 is the same as the underlying second type epitaxial layer 02 but without the extrinsic intentional doping of the second type epitaxial layer 02. In some embodiments, the re-growth layer 04 can have some intrinsic doping levels or without doping levels. In some embodiments, the material growth parameters, such as the ambient/gas pressure, the power, and the material for the re-growth process are the same or similar as that of the first type epitaxial layer 01 and/or second type epitaxial layer 02. The material of the re-growth layer 04 must be lattice matched with the light emitting layer 03, the first type epitaxial layer 01 and/or the second type epitaxial layer 02. Preferably, the material of the re-growth layer 04 is monocrystal, the material of the first epitaxial layer 01 is monocrystal and the material of the second epitaxial layer 02 is monocrystal. Furthermore, the material of the re-growth layer 04 is one or more of GaAs, InGaAs, GaP, GaN, InGaN, AlGaN, AlInP, GaInP, AlGaInP, AIP, InP, AlN, and/or InN, etc., or any combinations thereof, preferably one or more of GaP, AlP, GaAs, InP, AlInP, GaInP, AlN, GaN, and/or InN, or any combinations thereof. In another embodiment, the material of the re-growth layer 04 is without intentional doping ions and is not the same as the material of the first type epitaxial layer or the material of the second type epitaxial layer 02.
The resistance of the re-growth layer 04 is higher than the resistance of the light emitting layer 03 and the re-growth layer 04 is not electrically conductive, thereby ensuring the normal work of the micro LED structures, and stopping the carries spreading outside the light emitting layer 03. Preferably, the band gap of the re-growth layer 04 is greater than the band gap of the light emitting layer 03. Furthermore, the thickness of the re-growth layer 04 is less than the thickness of the light emitting layer 03, preferably, the thickness of the re-growth layer 04 is not more than 10 nm or 100 nm. In another embodiments, the thickness of the re-growth layer 04 is equal to or more than the thickness of the light-emitting layer 03.
Hereinafter, the detail of the micro LED panel and the method of manufacturing the micro LED panel will be described in consistent with the figures.
The micro LED panel of embodiment 1 comprises a micro LED structure array. Referring to
The mesa structure from bottom to top comprises: a first type epitaxial layer 01, a light emitting layer 03 and a second type epitaxial layer 02. The re-growth layer 04 is grown on the whole sidewall of the first type epitaxial layer 01, on the whole sidewall of the light emitting layer 03, and on part of the sidewall of the second type epitaxial layer 02. Furthermore, the re-growth layer 04 is very thin such as 5 nm, so the re-growth layer 04 is transparent in some embodiments.
A dielectric layer 05 is formed between the adjacent mesa structures. Furthermore, the dielectric layer 05 is formed on the surface of the re-growth layer 04 between the adjacent mesa structures. The top end of the re-growth layer 04 further extrudes into the dielectric layer 05. Preferably, the top end of the re-growth layer 04 is connected to the adjacent light emitting layer 03 and the adjacent first type epitaxial layer 01. Additionally, the top end of the re-growth layer 04 extruded 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. Additionally, the material of the dielectric layer 05 is transparent in some embodiments.
Herein, the top of the re-growth layer 04 is higher than the top of the light emitting layer 03, and, the bottom of the re-growth layer 04 is aligned with the bottom of the first type epitaxial layer 01, and further, the re-growth layer 04 is formed at the bottom of the first type epitaxial layer 01. An opening is formed in the re-growth layer 04 and 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 connected structure 07 is formed in the opening and formed at the bottom of the bottom contact 06.
In another embodiment, referring to
Additionally, the top contact 09 and the 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 continuously formed on the whole micro LED panel in the embodiment. In another embodiment, referring to
In some embodiments, the method of manufacturing the aforementioned micro LED panel in this embodiment 1 comprises the following steps.
Referring to
Herein, the epitaxial structure includes a first type epitaxial layer 01, a light emitting layer 03 and a second type epitaxial layer 02 from top down. The material of the semiconductor substrate 00′ can be GaN, GaAs, etc. The epitaxial structure is grown on the substrate 00′.
Referring to
Herein, the epitaxial structure is etched from top down by a conventional plasma etching process.
Referring to
Herein, the first mask pattern R1 is formed by a conventional photolithography process. The first mask pattern R1 is formed covering the sidewall of the light emitting layer 03, the top and the sidewall of the first type epitaxial layer 01, and part of the second type epitaxial layer 02.
Referring to
Herein, 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.
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, then the re-growth layer 04 can be formed on the whole sidewall of first type epitaxial layer 01, the whole sidewall of the light emitting layer 03 and part of the sidewall of the second type epitaxial layer 02. Therefore, the position of the re-growth layer 04 is decided by the bottom of the first mask pattern R1.
Then, step 4 additionally includes removing the first mask pattern R1.
Herein, the first mask pattern R1 is removed by a chemical etching process.
Referring to
Herein, the re-growth layer 04 is directly grown on the whole sidewall of the light emitting layer 03, on the top and the whole sidewall of the first type epitaxial layer 01, on part of the sidewall of the second type epitaxial layer 02 and deposited on the top surface of first dielectric layer 01. In this re-growth process, the temperature is 400° C. to 1000° C., and the re-growth time is 5 seconds to 1000 seconds. The material for re-growth 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, the re-growth layer 04 is further formed at least part of the sidewall of the second type epitaxial layer 02 when the top of the first dielectric layer 01 is lower than the bottom of the light emitting layer 03.
In another embodiment, referring to
Referring to
Herein, referring to
In another embodiment, step 7 comprises: forming a second dielectric layer 05″ on the re-growth layer 04 and forming an opening in the second dielectric layer 05″ on the first type epitaxial layer 01, and filling a bottom contact 06 in the opening. Herein, the second dielectric layer 05″ is deposited on the surface of the re-growth layer 04 by a conventional chemical vapor deposition process. Then, an opening is formed in the second dielectric layer 02 and in the re-growth 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.
In another embodiment, the bottom contact 06 can be formed before depositing the re-growth layer 04. Then, depositing the re-growth layer 04 on the sidewall of the light emitting layer 03, the sidewall and the top of the first type epitaxial layer 01 and on the bottom contact 06. Next, forming the second dielectric layer 02 on the re-growth layer 04. Finally, forming an opening in the second dielectric layer 02 and the re-growth layer 04, to expose the bottom contact 06.
Referring to
Herein, the material of the bottom connected structure 07 is deposited into the opening and on the bottom contact 06 by a conventional vapor deposition process.
Referring to
Herein, the semiconductor substrate 00′ with the epitaxial structure is firstly turned upside down. Then, the bottom connected structure 07 is bonded with a pad of the IC backplane 00. After the bonding process, the semiconductor substrate 00′ is removed by a conventional removing process, such as a laser lift-off method.
Referring to
Herein, referring to
In some embodiments, herein, the dielectric layer 05 in
The micro LED panel of embodiment 2 comprises a micro LED structure array.
Referring to
The mesa structure from bottom to top comprises: a first type epitaxial layer 01, a light emitting layer 03 and a second type epitaxial layer 02. The re-growth layer 04 is grown at least on the sidewall of the light emitting layer 03. Furthermore, the re-growth layer 04 is grown at the whole sidewall of the light emitting layer 03, on part of the first type epitaxial layer 01 and the whole sidewall of the second type epitaxial layer 02. An inclined angle of the re-growth 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 re-growth layer 03 further extrudes along the top surface of the dielectric layer 05. The re-growth layer 04 along the dielectric layer 05 is parallel to the bottom surface of the second type epitaxial layer 02. Additionally, the top end of the re-growth layer 04 extruded along and on the top of the dielectric layer 05 is connected to the adjacent light emitting layers 03 and the adjacent second type epitaxial layers 02. Furthermore, the re-growth layer 04 is very thin not more than 10 nm, such as 5 nm, so the re-growth layer 04 is transparent in some embodiments.
Furthermore, the bottom of the re-growth layer 04 is lower than the bottom of the light emitting layer 03. And the top of the re-growth layer 04 is aligned with the top of the second type epitaxial layer 02.
The dielectric layer 05 is further formed at the bottom of the mesa structures. 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 connected structure 07 is formed in the opening at the bottom of the bottom contact 06. Additionally, the material of the dielectric layer 05 is transparent in some embodiments.
Additionally, the top contact 09 and the 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 continuously formed on the whole micro LED panel. In another embodiment, the top conductive layer 08 is formed on the top contact and part of the top surface of the second type epitaxial layer 02.
The method of manufacturing the aforementioned micro LED panel in embodiment 2 comprises the following steps:
Referring to
Herein, the epitaxial structure comprises a first type epitaxial layer 01, a light emitting layer 03 and a second type epitaxial layer 02 from top down. The material of the semiconductor substrate 00′ can be GaN, GaAs, etc., on which the epitaxial structure is grown.
Referring to
Herein, the epitaxial structure is etched from top down by a conventional plasma etching process.
Referring to
Herein, the mask pattern R1 is formed covering the top and part of the sidewall of the first type epitaxial layer 01 by a photolithography method. The material of the mask pattern R1 is photo resist. In another embodiment, the material of the mask pattern R1 can be another material such as dielectric material.
Herein, the bottom of the mask pattern R1 is higher than the bottom of the first type epitaxial layer 01, so the re-growth layer 04 is further formed on part of the first type epitaxial layer 01. Therefore, the position of the re-growth layer 04 is decided by the bottom position of the mask pattern R1.
Referring to
Herein, the re-growth layer 04 is grown on the sidewall of the light emitting layer 03, on the sidewall of the second epitaxial layer 02, on part of the sidewall of the first epitaxial layer 01 and on the exposed top surface of the semiconductor substrate 00′. In this re-growth process, the temperature is 400° C. to 1000° C., and the re-growth time is 5 seconds to 1000 seconds. The material for re-growth process is the same as the material of the first type epitaxial layer and the material of the second type epitaxial layer but without intentional doping ions.
Referring to
Herein, the mask pattern R1 is removed by a conventional chemical etching process.
Referring to
Herein, referring to
In some embodiments, the step 6 comprises the following steps: firstly, an initial dielectric layer is deposited on the re-growth layer 04, on the sidewall and the 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 the 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 sidewall and the top of the mesa structure, and covers the top contact 06, to form the dielectric layer 05. Next, an opening is formed in the dielectric layer and exposing the bottom contact 06. The dielectric layer 05 is formed by the initial dielectric layer and the other dielectric layer.
Referring to
Herein, the material of the bottom connected structure 07 is deposited into the opening and on the bottom contact 06 by a conventional vapor deposition process.
Referring to
Herein, the semiconductor substrate 00′ with the epitaxial structure is firstly turned upside down. Then, the bottom connected structure 07 is bonded with a pad of the IC backplane 00. After the bonding process, the semiconductor substrate 00′ is removed by a conventional removing process, such as a laser lift-off method.
Referring to
Herein, the top contact 09 is deposited on the top of the second type epitaxial layer 02 with a mark protecting the other region. Then, a top conductive layer 08 is deposited on the second epitaxial layer 02 by a conventional vapor deposition process.
To resolve the problem in the related technologies, a micro LED panel is provided in the embodiments of the present invention.
The micro LED panel of embodiment 3 comprises a micro LED structure array.
Referring to
A dielectric layer 05 is formed between the adjacent mesa structures. The dielectric layer 05 is further formed at the bottom of the mesa structure. Preferably, the material of the dielectric layer 05 is one or more of SiO2, SiNx, Al2O3, AlN, HfO2, TiO2, and/or ZrO2, etc. Additionally, the material of the dielectric layer 05 is transparent in some embodiments.
A bottom contact 06 and a bottom connected structure 07 are formed in the dielectric layer 05 at the bottom of the first type epitaxial layer 01. Additionally, the top contact 09 and the 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 continuously formed on the whole micro LED panel in the embodiment. In another embodiment, the top conductive layer 08 is formed on the top contact 09 and part of the top surface of the second type epitaxial layer 02.
The top end of the re-growth layer 04 further extrudes along the top surface of the dielectric layer 05. Furthermore, the re-growth layer 04 extruded along the dielectric layer 05 is parallel to the top surface of the dielectric layer 05. Preferably, the re-growth layer 04 extruded along the top of the dielectric layer 05 is connected to the adjacent second type epitaxial layer 02. Additionally, the re-growth layer 04 is further formed at the bottom surface of the first type epitaxial layer 01. The bottom contact 06 is further formed in the re-growth layer 04.
The method of manufacturing the aforementioned micro LED panel in this embodiment 3, comprises the following steps.
Referring to
Herein, the epitaxial structure includes a first type epitaxial layer 01, a light emitting layer 03 and a second type epitaxial layer 02 from top down. The material of the semiconductor substrate 00′ can be GaN, GaAs, etc., on which the epitaxial structure is grown.
Referring to
Herein, the epitaxial structure is etched from top down by a conventional plasma etching process.
Referring to
Herein, the re-growth layer 04 is re-grown on the whole sidewall of the light emitting layer 03, the first type epitaxial layer 01 and the second type epitaxial layer 02. Furthermore, the re-growth layer 04 is further 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 re-growth process, the temperature is 400° C. to 1000° C., and the re-growth time is 5 seconds to 1000 seconds. The material for re-growth process is the same as the material of the first type epitaxial layer and the material of the second type epitaxial layer but without intentional doping ions.
In another embodiment, the re-growth layer 04 is further grown on at least part of the sidewall of the second type epitaxial layer 02, on the whole sidewall of the first type epitaxial layer 01 and on the whole sidewall of the light emitting layer 03, but without growing on the semiconductor substrate 00′. Therefore, in step 3, before forming the re-growth layer 04, step 3 further includes: forming a mask pattern covering part of the sidewall of the second type epitaxial layer 02. Then, the re-growth layer is grown on the whole sidewall of the light emitting layer 03, the whole sidewall of the first type epitaxial layer 01 and part of the sidewall of the second type epitaxial layer 02. After forming the re-growth layer 04, step 3 further includes: removing the mask pattern.
In some embodiments, the re-growth layer 04 is further grown on at least part of the sidewall of the first type epitaxial layer 01, on the whole sidewall of the light emitting layer 03 and on the whole sidewall of the second type epitaxial layer 02, but without growing on the top of the first type epitaxial layer 01. Therefore, in step 3, before forming the re-growth layer 04, step 3 further includes: forming a mask pattern covering the top and part of the sidewall of the first type epitaxial layer 01. Then, the re-growth layer 04 is grown on the whole sidewall of the light emitting layer 03, the whole sidewall of the second type epitaxial layer 02 and part of the sidewall of the first type epitaxial layer 01. After forming the re-growth layer 04, step 3 further includes: removing the mask pattern.
In some embodiments, the re-growth layer 04 is grown on at least part of the sidewall of the first type epitaxial layer 01 and at least part of the second type epitaxial layer 02, on the whole sidewall of the light emitting layer 03, without growing on the top of the first type epitaxial layer 01 and on the top of the substrate 00′. Therefore, before forming the re-growth layer 04, step 3 further includes: forming a first mask pattern covering the top and part of the sidewall of the first type epitaxial layer 01, and covering part of the sidewall of the second type epitaxial layer 02 and the exposed top surface of the semiconductor substrate 00′. Then, the re-growth layer 04 is grown on the whole sidewall of the light emitting layer 03, the whole sidewall of the second type epitaxial layer 02 and the sidewall of the first type epitaxial layer 01. After forming the re-growth layer 04, step3 further includes: removing the mask pattern.
Referring to
Herein, referring to
In another embodiment, a dielectric layer is firstly deposited on the re-growth ring, on the sidewall and the top of the first type epitaxial layer. Then, an opening is formed in the dielectric layer on the first type epitaxial layer. Next, the bottom contact is formed in the opening and connected to the first type epitaxial layer.
In some embodiments, the step 4 comprises the following steps: firstly, an initial dielectric layer is deposited on the re-growth ring, on the sidewall and the 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 the bottom contact is deposited on the first type epitaxial layer. Then, another dielectric layer is deposited on the initial dielectric layer and the sidewall and the top of the mesa structure, and covers the top contact, to form the completed dielectric layer. Next, an opening is formed in the dielectric layer and exposing the bottom contact.
The opening is formed by a conventional plasma etching process and the bottom contact 06 is formed be a conventional vapor deposition process.
In another embodiment, the bottom contact 06 can be formed before depositing the re-growth layer 04. Then, the re-growth layer 04 is deposited on the sidewall of the light emitting layer 03, the sidewall and the top of the first type epitaxial layer 01 and on the bottom contact 06. Next, the dielectric layer 05 is formed on the re-growth layer 04. Finally, an opening is formed in the dielectric layer 05 and the re-growth layer 04, to expose the bottom contact 06.
Referring to
Herein, the material of the bottom connected structure 07 is deposited into the opening and on the bottom contact by a conventional vapor deposition process.
Referring to
Herein, the semiconductor substrate 00′ with the epitaxial structure is firstly turned upside down. Then, the bottom connected structure 07 is bonded with a pad of the IC backplane 00. After the bonding process, the semiconductor substrate 00′ is removed by a conventional removing process, such as a laser lift-off method.
Referring to
Herein, the top contact 09 is deposited on the top of the second type epitaxial layer 02 with a mask protecting the other region, and then the mask is removed. Then, a top conductive layer 08 is deposited on the second epitaxial layer 02 by a conventional vapor deposition process.
The micro LED panel of embodiment 4 comprises a micro LED structure array.
Referring to
The mesa structure from bottom to top consists of or comprises: a first type epitaxial layer 01, a light emitting layer 03 and a second type epitaxial layer 02. Herein, the re-growth layer 04 is grown on the whole sidewall of the first type epitaxial layer 01, the whole sidewall of the light emitting layer 03 and the whole sidewall of the second type epitaxial layer 02. Furthermore, the re-growth layer 04 is fully filled in the space between the adjacent mesa structures. That is to say, the re-growth layer 04 is further used for isolating the sidewall of the mesa structure from each other. The top width of the re-growth layer 04 is the same as the top width of the space between the adjacent mesa structures.
Furthermore, the re-growth layer 04 is very thin not more than 10 nm, such as 5 nm, so the re-growth layer 04 is transparent in some embodiments. The re-growth layer 04 is further formed at the bottom of the mesa structure. The bottom contact 06 and the bottom connected structure 07 are formed in the re-growth layer 04 below the mesa structure and the bottom contact 06 and the bottom connected structure 07 are electrically connected to the first type epitaxial layer 01.
Additionally, the top contact 09 and the 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 continuously formed on the whole micro LED panel in the embodiment. In another embodiment, referring to
The method of manufacturing the aforementioned micro LED panel in this embodiment 4 comprises the following steps.
Referring to
Herein, the epitaxial structure comprises a first type epitaxial layer 01, a light emitting layer 03 and a second type epitaxial layer 02 from top down. The material of the semiconductor substrate 00′ can be GaN, GaAs, etc., on which the epitaxial structure is grown.
Referring to
Herein, the epitaxial structure is etched from top down by a conventional plasma etching process.
Referring to
Herein, the re-growth layer 04 is re-grown on the whole sidewall of the light emitting layer 03, the first type epitaxial layer 01 and the second type epitaxial layer 02. Furthermore, the re-growth layer 04 is further 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 re-growth process, the temperature is 400° C. to 1000° C., and the re-growth time is 5 seconds to 1000 seconds. The material for re-growth 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.
Referring to
Herein, the opening is formed by a conventional plasma etching process and the bottom contact 06 is formed be a conventional vapor deposition process.
In another embodiment, the bottom contact 06 can be formed before depositing the re-growth layer 04. Then, depositing the re-growth layer 04 on the sidewall of the light emitting layer 03, the sidewall and the top of the first type epitaxial layer 01 and on the bottom contact 06. Finally, forming an opening in the re-growth layer 04, to expose the bottom contact 06.
Referring to
Herein, the material of the bottom connected structure 07 is deposited into the opening and on the bottom contact by a conventional vapor deposition process.
Referring to
Herein, the semiconductor substrate 00′ with the epitaxial structure is firstly turned upside down. Then, the bottom connected structure 07 is bonded with a pad of the IC backplane 00. After the bonding process, the semiconductor substrate 00′ is removed by a conventional removing process, such as a laser lift-off method.
Referring to
Herein, the top contact 09 is deposited on the top of the second type epitaxial layer 02 with a mask protecting the other region, and the mask is removed after the top contact 09 is formed. Then, a top conductive layer 08 is deposited on the second epitaxial layer 02 by a conventional vapor deposition process.
The micro LED panel of embodiment 5 comprises a micro LED structure array.
Referring to
The mesa structure from bottom to top comprises: a first type epitaxial layer 01, a light emitting layer 03 and a second type epitaxial layer 02. Herein, the re-growth layer 04 is grown on the whole sidewall of the first type epitaxial layer 01, the whole sidewall of the light emitting layer 03 and the whole sidewall of the second type epitaxial layer 02. Furthermore, the re-growth layer 04 is fully filled in the space between the adjacent mesa structures. The top width of the re-growth layer 04 is the same as the top width of the space between the adjacent mesa structures.
Furthermore, the re-growth layer 04 is very thin not more than 10 nm, such as 5 nm, so the re-growth layer 04 is transparent in some embodiments. A dielectric layer 05 is further formed at the bottom of the mesa structure and the bottom of the re-growth layer 04. The bottom connected 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. Additionally, the material of the dielectric layer 05 is transparent in some embodiments.
Additionally, the top contact 09 and the top conductive layer 08 are formed on the top of the second type epitaxial layer. In some embodiments, herein, the top conductive layer 08 is formed on the top contact and part of the top surface of the second type epitaxial layer 02.
The method of manufacturing the aforementioned micro LED panel in this embodiment 5 comprises the following steps.
Referring to
Herein, the epitaxial structure includes a first type epitaxial layer 01, a light emitting layer 02 and a second type epitaxial layer 03 from top down. The material of the semiconductor substrate 00′ can be GaN, GaAs, etc., on which the epitaxial structure is grown.
Referring to
Herein, the epitaxial structure is etched from top down by a conventional plasma etching process.
Referring to
Herein, the re-growth layer 04 is re-grown on the whole sidewall of the light emitting layer 03, the first type epitaxial layer 01 and the second type epitaxial layer 02, and. Furthermore, the re-growth layer 04 is further formed on the top surface of the first type epitaxial layer 01 and on the exposed top surface of the semiconductor substrate 00′. Then, the re-growth layer 04 is etched and stop on the top of the mesa structure, exposing the top of the mesa structure.
In this re-growth process, the temperature is 400° C. to 1000° C., and the re-growth time is 5 seconds to 1000 seconds. The material for re-growth 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.
Referring to
Herein, the dielectric layer 05 is deposited on the top of the first type epitaxial layer 01 and the top of the re-growth layer 04 by a conventional chemical vapor deposition process.
Referring to
Herein, the opening is formed by a conventional plasma etching process and the bottom contact 06 is formed be a conventional vapor deposition process.
In another embodiment, the bottom contact can be formed before depositing the re-growth layer. Then, depositing the re-growth layer on the sidewall of the light emitting layer, the sidewall and the top of the first type epitaxial layer and on the bottom contact. Next, forming the dielectric layer on the re-growth layer. Finally, forming an opening in the dielectric layer and the re-growth layer, to expose the bottom contact.
Referring to
Herein, the material of the bottom connected structure 07 is deposited into the opening and on the bottom contact 06 by a conventional vapor deposition process.
Referring to
Herein, the semiconductor substrate 00′with the epitaxial structure is firstly turned upside down. Then, the bottom connected structure 07 is bonded with a pad of the IC backplane 00. After the bonding process, the semiconductor substrate 00′ is removed by a conventional removing process, such as a laser lift-off method.
Referring to
Herein, the top contact 09 is deposited on the top of the second type epitaxial layer 02 with a mask protecting the other region, and the mask is removed after the top contact 09 is formed. Then, a top conductive layer 08 is formed on the top of the second type epitaxial layer 02 and on the top and sidewall of the top contact 09 with another mask protecting the other region, and the other mask is removed after the top conductive layer 08 is formed. Furthermore, the top conductive layer 08 is formed on part of the top surface of the second type epitaxial layer 02 without cover the whole second type epitaxial layer 02. The top contact 09 and the top conductive layer 08 are formed by a conventional vapor deposition process.
It is understood by those skilled in the art that, the micro display panel is not limited by the structure mentioned above, and may include more or less components than those as illustrated, or some components may be combined, or a different component may be utilized.
It is understood by those skilled in the art that, all or part of the steps for implementing the foregoing embodiments may be implemented by hardware, or may be implemented by a program which instructs related hardware. The program may be stored in a flash memory, in a conventional computer device, in a central processing module, in an adjustment module, etc.
The above descriptions are merely embodiments of the present disclosure, and the present disclosure is not limited thereto. A modifications, equivalent substitutions and improvements made without departing from the conception and principle of the present disclosure shall fall within the protection scope of the present disclosure.
Further embodiments also include various subsets of the above embodiments including embodiments as shown in
Although the detailed description contains many specifics, these should not be construed as limiting the scope of the invention but merely as illustrating different examples and aspects of the invention. It should be appreciated that the scope of the invention includes other embodiments not discussed in detail above. For example, the approaches described above 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 (VCSEL), photodetectors, micro-electro-mechanical system (MEMS), silicon photonic devices, power electronic devices, and distributed feedback lasers (DFB). Examples of other control circuitry include current drivers, voltage drivers, trans-impedance amplifiers, and logic circuits.
The preceding description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the embodiments described herein and variations thereof. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may 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 following claims and the principles and novel features disclosed herein.
Features of the present invention can be implemented in, using, or with the assistance of a computer program product, such as a storage medium (media) or computer readable storage medium (media) having instructions stored thereon/in which can be used to program a processing system to perform any of the features presented herein. The storage medium can include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM or other random access solid state memory devices, and may 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. Memory optionally includes one or more storage devices remotely located from the CPU(s). Memory or alternatively the non-volatile memory device(s) within the memory, comprises a non-transitory computer readable storage medium.
Stored on any machine readable medium (media), features of the present invention can be incorporated in software and/or firmware for controlling the hardware of a processing system, and for enabling a processing system to interact with other mechanisms utilizing the results of the present invention. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments/containers.
It will be understood that, although the terms “first,” “second,” etc. may 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.
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.
As used herein, the term “if”' may be construed to mean “when” or “upon” or “in response to determining” or “in accordance with a determination” or “in response to detecting,” that a stated condition precedent is true, depending on the context. Similarly, the phrase “if it is determined [that a stated condition precedent is true]” or “if [a stated condition precedent is true]” or “when [a stated condition precedent is true]” may be construed to mean “upon determining” or “in response to determining” or “in accordance with a determination” or “upon detecting” or “in response to detecting” that the stated condition precedent is true, depending on the context.
The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the claims to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain principles of operation and practical applications, to thereby enable others skilled in the art to best utilize the invention and the various embodiments.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2022/075278 | 1/31/2022 | WO |
