Micro light emitting diode, micro light emitting diode device, display and method thereof

Abstract

The invention relates to various aspects of a [mu]-LED or a [mu]-LED arrangement for augmented reality or light applications, in particular in the automotive field. The [mu]-LEDs are characterized by particularly small dimensions in the range of several [mu] m.

Description

[0001] This invention is a divisional application of the parent application, which is filed on January 29, 2020, with application number 202080023800.9 and invention title "Miniature Light Emitting Diode, Miniature Light Emitting Diode Device, Display and Method Thereof" (PCT International Application PCT / EP2020 / 052191 entered the Chinese National Phase).

[0002] This patent application claims priority to the following German patent applications: DE 10 2019 201114.4, dated January 29, 2019; DE 10 2019 111 766.6, dated May 7, 2019; DE 10 2019 112 124.8, dated May 9, 2019; DE 10 2019 116 313.7, dated June 14, 2019; DE 10 2019 131 506.9, dated November 21, 2019; DE 10 2019 118 251.4, dated July 5, 2019; DE 10 2019 118 082.1, dated July 4, 2019; and DE 10 2019, dated March 29, 2019. 108 260.9, DE 10 2019 on September 20, 2019 125 349.7, DE 10 2019 on May 13, 2019 112 490.5, DE 10 2019 on May 14, 2019 112 604.5, DE 10 2019 on May 14, 2019 112 609.6, DE 10 2019 on January 31, 2019 102 509.5, DE 10 2019 on June 7, 2019 115 479.0, DE 10 2019 on May 14, 2019 112 616.9, DE 10 2019 on May 23, 2019 113791.8, DE 10 2019 110 499.8 on April 23, 2019, DE 10 2019 110523.4 on April 23, 2019, DE 10 2019 130 934.4 on November 15, 2019, DE 10 2019 114321.7 on May 28, 2019, DE 10 2019 127 425.7 on October 11, 2019, DE 10 2019 112639.8 on May 14, 2019, DE 10 2019 112 605.3 on May 22, 2019 113636.9, DE 10 2019 103 365.9 on February 11, 2019, DE 10 2019 116312.9 on June 14, 2019, DE 10 2019 115 991.1 on June 12, 2019, DE 10 2019 125875.8 on September 25, 2019, DE 10 2019 127 424.9 on October 11, 2019, DE 10 2019 118085.6 on July 4, 2019, DE 10 2019 125 336 on September 20, 2019.5. DE 10 2019 113793.4 on May 23, 2019; DE 10 2019 110 500.5 on April 23, 2019; DE 10 2019 111 767.4 on May 7, 2019; DE 10 2019 121 672.9 on August 12, 2019; DE 10 2019 118 084.8 on July 4, 2019; DE 10 2019 113 768.3 on May 23, 2019; DE 10 2019 113 792.6 on May 23, 2019; DE 10 2019 110 on April 23, 2019. 497.1, DE 10 2019 114 442.6 dated May 29, 2019, DE 10 2019 129 209.3 dated October 29, 2019, DE 10 2019 130 821.6 dated November 14, 2019, and DE10 2019 130 866.6 dated November 15, 2019, the disclosures of which are incorporated herein by reference, and also claim Danish patent applications DK PA201970059, DK PA201970060, and DK, dated January 29, 2019. The patent claims priority to PA201970061, the disclosure of which is incorporated herein by reference, and also to U.S. patent application US 62 / 937,552, dated November 19, 2019, the disclosure of which is incorporated herein by reference. Technical Field

[0003] This invention relates to miniature light-emitting diodes, miniature light-emitting diode devices, and displays. Background Technology

[0004] The ongoing developments in the Internet of Things (IoT) and communications fields have opened doors to a variety of new applications and designs. These designs and applications offer greater effectiveness and efficiency for development, service, and manufacturing purposes.

[0005] One aspect of the new design involves augmented reality, or virtual reality. The general definition of “augmented reality” is: “an interactive experience of a real environment in which objects in the real world are extended by computer-generated perceptible information.”

[0006] Information is primarily conveyed through visualization, but not limited to visual perception. Sometimes, tactile or other sensory perceptions can be used to augment reality. In the case of visualization, the overlaid sensory visual information can be constructive—that is, supplementing the natural environment—or non-constructive, such as by covering a portion of the natural environment. In some applications, interaction with the overlaid sensory information may also occur in one or another manner. Thus, augmented reality enhances the user's continuous perception of the real environment.

[0007] In contrast, "virtual reality" replaces the user's real environment with a completely simulated one. In other words, while users can perceive the real world at least partially in an augmented reality environment, the environment in virtual reality is completely simulated and may differ significantly from reality.

[0008] Augmented reality (AR) can be used to improve natural environmental conditions, thereby enriching the user experience or supporting them in performing certain tasks. For example, users can use displays with AR capabilities to assist them in performing certain tasks. By overlaying information about real objects to provide clues to the user, it provides additional information, enabling them to act faster, safer, and more efficiently during manufacturing, repair tasks, or other services. In the medical field, AR technology can be used to guide and support doctors in diagnosing and treating patients. In development, engineers can directly experience their test results, making it easier to evaluate the outcomes. In the tourism or events industry, AR can provide users with additional information about attractions, history, and more. AR can also support learning activities or tasks. Summary of the Invention

[0009] The following introduction illustrates various aspects of μ (micro) displays in automotive and augmented reality applications. These aspects include devices, displays, controls, process techniques, and other suitable features for augmented reality and automotive applications. This includes aspects designed to generate light through indicators, displays, etc. Additionally, aspects of control circuitry, power supplies, and optical coupling outputs, light guiding, and light focusing are listed, along with applications of such devices, explained using various examples.

[0010] Because of the various limitations and challenges posed by the small size of the light-generating components, combining various aspects is not only advantageous but often necessary. For ease of handling, this disclosure is divided into several parts with similar topics. However, it should not be explicitly understood that features of one topic cannot be combined with other topics. Rather, aspects from different subject areas must be combined to create displays for augmented reality or other applications or in the automotive field.

[0011] To consider the following solutions, some terms and expressions should be explained to define common and shared understanding. For clarity, the listed terms are generally used herein. However, in individual cases, they may deviate from the intended interpretation, where such deviation is identifiable.

[0012] "Active Matrix Display"

[0013] The term "active matrix display" originally referred to liquid crystal screens containing a matrix of thin-film transistors controlled by LCD (liquid crystal display) pixels. Each individual pixel has a circuit with active components (mainly transistors) and power connections. However, this technology should not be limited to liquid crystals at present, but should specifically refer to the control of μ-LEDs (micro-light-emitting diodes) or μ displays.

[0014] "Active Matrix Carrier Substrate"

[0015] An "active matrix carrier substrate" or "active matrix backplane" refers to the driving device for the light-emitting diodes (LEDs) of a display with thin-film transistor (TFT) circuitry. Here, these circuits can be integrated into or applied to the backplane. The "active matrix carrier substrate" has one or more interface contacts that form an electrical connection with the μ-LED display structure. Therefore, the "active matrix carrier substrate" can be part of or carry an active matrix display.

[0016] "Active layer"

[0017] An active layer is a layer in an optoelectronic device or light-emitting diode (LED) where charge carriers recombine. In its simplest form, an active layer is characterized by regions of two adjacent semiconductor layers with different conductivity types. More complex active layers include quantum wells (see related description), multiple quantum wells, or other structures with additional properties. Structural and material systems can also be used to define the band gap in the active layer (see related description), which defines the wavelength and thus the color of light.

[0018] "Alvarez Lens Device"

[0019] The optical path of the video glasses can be adjusted by using Alvarez lens pairs. The adjustment optics include Alvarez lens devices, particularly rotatable variants with moiré lens devices. Here, beam deflection is determined by the first derivative of the individual phase plate morphologies, approximately z = ax² + by² + cx + dy + e for the radiation direction z and the transverse directions x and y, and is determined by the offset of the two phase plates arranged in pairs in the transverse directions x and y. For alternative designs, pivotable prisms are provided in the adjustment optics.

[0020] Augmented Reality (AR)

[0021] This is an interactive experience of a real-world environment, where the filmed project is located in the real world and enhanced by computer-generated perceptible information. Augmented reality is understood as a computer-aided extension of the perception of reality through such computer-generated perceptible information. This information can appeal to all human senses. However, augmented reality often refers only to the visual representation of information, i.e., images or videos with computer-generated additional information or virtual objects added through fade-in / overlay. Applications and explanations of how augmented reality works can be found in the introduction to the examples and below.

[0022] "car"

[0023] "Automotive" generally refers to motor vehicles or the automotive industry. Therefore, the term is intended to include this branch, but also all other industry branches, including microdisplays or general luminous indicators with very high resolution and μ-LEDs.

[0024] "band gap"

[0025] The energy gap between the valence band and conduction band of a solid is called the band gap, also known as the band gap or band exclusion zone. Its electrical and optical properties depend largely on the size of the band gap. The size of the band gap is usually expressed in electron volts (eV). The band gap is used to distinguish metals, semiconductors, and insulators. The band gap can be tuned (i.e., changed) by various measures such as spatial doping to detune the crystal structure or by altering the material system. Material systems with a so-called direct band gap, where the maximum value of the valence band and the minimum value of the conduction band are superimposed in momentum space, allow electron-hole pairs to recombine with emitted light.

[0026] Bragg photogate

[0027] A Bragg fiber optic grating is a special optical interference filter etched into an optical waveguide. Wavelengths within the filter bandwidth near λB are reflected. Various methods are used to generate periodic modulation of the refractive index within the fiber core of the waveguide. This creates regions with high and low refractive indices that reflect light of specific wavelengths (bandstop). The center wavelength of the filter bandwidth in a single-mode fiber is determined by the Bragg condition.

[0028] "Directionality"

[0029] Directivity, or directionality, is used to describe the radiation characteristics of μ-LEDs or other light-emitting components. High directionality corresponds to highly directional radiation or a low-radiation cone. Typically, the goal is to achieve a high level of directional radiation to minimize crosstalk between light and adjacent pixels. Consequently, the brightness of the light-emitting component varies depending on the viewing angle, thus differing from a Lambertian emitter.

[0030] Directionality can be altered, for example, by mechanical or other means on the side used for emission. Besides lenses, this includes photonic crystals or columnar structures (pillar structures) arranged on the emission surface of the pixelated array or, in particular, on an arrangement of μ-LEDs. These create a virtual bandgap that reduces or prevents the light vector from diffusing along the emission surface.

[0031] "Far field"

[0032] The terms near field and far field describe the spatial regions surrounding components that emit electromagnetic waves and have distinct characteristics. Typically, these spatial regions are divided into three areas: the reactive near field, the transition field, and the far field. In the far field, electromagnetic waves propagate as plane waves, independent of the radiating element.

[0033] "Screen window effect"

[0034] The screen-door effect (SDE) is a permanently visible image artifact in digital video projectors. The term describes an undesirable, technically relevant dark distance between individual pixels or their projected information, taking the form of a screen. This distance originates from the construction, as the conductive circuitry used for control runs between the individual LCD segments, where light is swallowed up and cannot reach the screen. If small photoelectric light-emitting devices are used, particularly μ-LEDs, or the distance between individual LEDs is too large, the low packing density produced when viewing a single LED can result in a visible difference in pixel areas between bright and dark spots. This so-called screen-door effect is particularly noticeable when viewed from a smaller distance, especially in applications such as VR (virtual reality) glasses. When the illumination differences within a pixel persist periodically across the entire matrix arrangement, the sub-pixel structure is often perceived and annoying. Therefore, the screen-door effect should be avoided as much as possible in automotive and augmented reality applications.

[0035] "Flip Chip"

[0036] Flip chip assembly is a method of fabrication and connection technology used to contact unpackaged semiconductor chips via contact bumps known as "bumps." With flip chip assembly, the chip can be directly mounted without additional interconnects, with its effective contact surface facing down (towards the substrate / circuit carrier) above the bumps. This results in a particularly small housing size and shorter conductor length. Therefore, flip chips are especially suitable for electronic semiconductor components that contact on their back side. Such components may also require special transfer techniques, such as using an auxiliary carrier. In the case of flip chips, the radiation direction is typically opposite to the side of the contact surface.

[0037] "trigger"

[0038] A flip-flop, also commonly known as a bistable switching stage or bistable switching element, is an electronic circuit with two stable output signal states. The current state depends not only on the currently available input signal but also on the state that existed prior to the point in time being considered. There is no time correlation, only event correlation. Due to its bistable nature, a flip-flop can store one bit of data indefinitely. However, unlike other types of memory, a voltage supply must always be guaranteed. Flip-flops are a fundamental component of sequential circuits and an essential part of digital technology, thus forming a basic element in many electronic circuits, from quartz clocks to microprocessors. In particular, as a basic one-bit memory, it is a fundamental element of the static memory module used in computers. Some embodiments may use different types of flip-flops or other buffer circuits to store state information. Their respective input and output signals are digital, meaning they alternate between logical "false" and logical "true". These values ​​are also referred to as "low" 0 and "high" 1.

[0039] Head-up display

[0040] A head-up display (HUD) is a display system or projection device in which a user maintains a certain head posture or gaze as information is projected into the user's field of view. HUDs are augmented reality systems. In some cases, HUDs incorporate sensors that determine the direction or orientation of the user's gaze in space.

[0041] Horizontal LED

[0042] In the case of horizontal LEDs, the electrical connection is located on the common side of the LED. This is typically the back side of the LED, away from the light-emitting surface. Therefore, horizontal LEDs have contacts formed only on the surface side.

[0043] "Interference Filter"

[0044] An interference color filter is an optical component that uses the interference effect to filter light in a frequency-dependent manner (i.e., in a color-dependent manner for visible light).

[0045] "Collimation"

[0046] In optics, collimation refers to the parallel direction of diverging rays. The associated lens is called a collimator or condenser. A collimated beam contains mostly parallel rays and therefore has minimal scattering during propagation. Its use in this sense relates to the scattering of light emitted from a light source. A collimated beam emitted from a surface is highly dependent on the angle of radiation. In other words, the radiance (unit power per unit angle of a projected light source area) of a collimated light source varies with increasing angle. Light can be collimated in various ways, such as by using a special lens placed in front of the light source. Therefore, collimated light can also be considered as light with a high degree of directional dependence.

[0047] "Converter Materials"

[0048] Converter materials are materials suitable for converting light of a first wavelength into light of a second wavelength, shorter than the second. These include various permanent inorganic and organic dyes as well as quantum dots. Converter materials can be applied and constructed in a variety of processes.

[0049] "Lambert Launcher"

[0050] The so-called Lambertian radiation characteristic is required in many applications. This means that the luminescent surface ideally has a uniform radiation density on its surface, resulting in a vertically circular distribution of radiation intensity. Since humans can only assess brightness with their eyes (brightness is the luminous equivalent of illuminance), such Lambertian materials appear equally bright regardless of the viewing direction. This uniform, angle-independent brightness can be an important quality factor, especially for curved and flexible display surfaces, which is sometimes difficult to achieve with currently available displays due to their structure and LED technology.

[0051] LEDs and μ-LEDs are similar to Lambertian emitters and emit light at a large spatial angle. Depending on the application, further steps can be taken to improve radiation characteristics, or greater directionality can be attempted (see related notes).

[0052] "Conductivity type"

[0053] The term "conductivity type" refers to the majority (n- or p-type) charge carriers in a given semiconductor material. That is, a semiconductor material doped with n (negative) type is considered to be of n conductivity type. Similarly, if a semiconductor material is n-type, then it is n-type doped. The term "active" region in a semiconductor refers to the boundary region between an n-type doped layer and a p (positive)-type doped layer. Radiative recombination of p-type and n-type charge carriers occurs in this region. In some embodiments, the active region is further constructed and includes, for example, a quantum well or quantum dot structure.

[0054] "Light field display"

[0055] A display technology that projects raster images directly onto the retina of the eye is called a Virtual Retinal Display (VNA) or Light Field Display. The user gains the impression of a canvas floating in front of them. Light Field Displays can be provided as glasses, projecting raster images directly onto the user's retina. Using a Virtual Retinal Display, an image is created within the user's eye through direct projection of the retina. Light Field Displays are augmented reality systems.

[0056] "Plate printing" or "photolithography"

[0057] Photolithography is one of the core methods in semiconductor and microsystems technology, used to manufacture integrated circuits and other products. In this process, the image of a photomask is transferred onto a photosensitive photoresist through exposure. Subsequently, the exposed areas of the photoresist are dissolved (or the unexposed areas can also be dissolved when the photoresist cures under light). This forms a lithographic mask, which can be further processed through chemical and physical processes, such as applying material to the open areas or etching recesses in the open areas. The remaining photoresist can then be removed.

[0058] “μ-LED”

[0059] μ-LEDs are optoelectronic devices with edge lengths less than 70 μm, particularly less than 20 μm, and especially in the range of 1 μm to 10 μm. Another range is between 10 and 30 μm. This results in a range of several hundred μm. 2 Up to tens of μm 2 The area of ​​a μ-LED is approximately 60 μm², with an edge length of approximately 8 μm. In some cases, the edge length of a μ-LED is 5 μm or less, resulting in a size less than 30 μm². For example, the typical height of such a μ-LED is between 1.5 μm and 10 μm.

[0060] Besides classic lighting applications, μ-LEDs are primarily used in displays. Here, μ-LEDs form pixels or subpixels and emit light of a specified color. Due to their small pixel size and high density at close range, μ-LEDs are also suitable for small, monolithic displays used in AR applications.

[0061] Due to the extremely small size of μ-LEDs, their production and processing are significantly more difficult compared to previous large LEDs. This also applies to other components such as contact lenses, packaging, and lenses. Some aspects feasible in large optoelectronic components cannot be achieved in μ-LEDs, or must be achieved in different ways. In this respect, μ-LEDs are therefore significantly different from traditional LEDs, i.e., light-emitting elements with an edge length of 200 μm or more.

[0062] μ-LED array

[0063] See Microdisplay

[0064] "Miniature display"

[0065] A microdisplay, or μ-LED array, is a matrix with a large number of pixels arranged in prescribed rows and columns. Functionally, a μ-LED array typically forms a matrix primarily composed of μ-LEDs of the same type and color. Therefore, it provides a larger surface area for illumination. On the other hand, the purpose of a μ-display is to transmit information, which often also necessitates different colors or positional control for each individual pixel or subpixel. A microdisplay can consist of multiple μ-LED arrays, formed together on a backplane or other carrier. However, μ-LED arrays can also be used to form microdisplays.

[0066] Each pixel is on the order of a few μm, similar to a μ-LED. Therefore, a μ-display with 1920×1080 pixels, each with a 5μm μ-LED, and directly adjacent pixels has an overall size of 10 mm². In other words, a microdisplay or μ-LED array is a small-scale device implemented using μ-LEDs.

[0067] Microdisplays or μ-LED arrays can be formed from a single, identical component. The μ-LEDs in a μ-LED array can be formed monolithically. Such microdisplays or μ-LED arrays are called monolithic μ-LED arrays or microdisplays.

[0068] Alternatively, both components can be formed by growing μ-LEDs individually on a substrate and then arranging them individually or in groups on a carrier using a so-called pick-and-place process, maintaining a certain distance between them. Such a microdisplay or μ-LED array is referred to as non-monolithic. In a non-monolithic microdisplay or μ-LED array, other distances between individual μ-LEDs are also possible. These distances can be flexibly chosen depending on the application and implementation. Therefore, such a microdisplay or μ-LED array can also be referred to as a pitch-extended component. In a pitch-extended microdisplay or μ-LED array, the μ-LEDs are arranged at greater distances when delivered to the carrier than they are on the growth substrate. In a non-monolithic microdisplay or μ-LED array, each individual pixel may each include a blue-emitting μ-LED, a green-emitting μ-LED, and a red-emitting μ-LED.

[0069] To leverage the advantages of both monolithic and non-monolithic μ-LED arrays within a single module, monolithic μ-LED arrays can be combined with non-monolithic μ-LED arrays in a microdisplay. This allows the microdisplay to be used for different functions or applications. Such a display is called a hybrid display.

[0070] "μ-LED nanopillars"

[0071] μ-LED nanopillars are typically a stack of semiconductor layers with an active layer, thus forming a μ-LED. The edge length of a μ-LED nanopillar is less than its height. For example, the edge length of a μ-LED nanopillar is approximately 10 nm to 300 nm, while the height of the device may be 200 nm to 1 μm or higher.

[0072] "μ column"

[0073] μ-pillars or pillars specifically refer to a geometric structure, particularly a rod or bar, or generally a slender, cylindrical structure. The spatial dimensions of manufactured μ-pillars range from μm to nm. Therefore, nanopillars are also included herein.

[0074] "Nanopillars"

[0075] In nanotechnology, nanopillars are a design concept for nanoscale objects. Each of them ranges in size from approximately 10 nm to 500 nm. They can be synthesized from metallic or semiconducting materials. The aspect ratio (length divided by width) is 3 to 5. Nanopillars are made through direct chemical synthesis. A combination of ligands acts as a shape control agent and attaches to different faces of the nanopillar with varying strengths. This allows for different designs of nanopillars with different growth rates to produce an elongated object. μLED nanopillars are such nanopillars.

[0076] Miniature LED

[0077] Its size ranges from 100μm to 750μm, especially in the range greater than 150μm.

[0078] Moiré effect and Moiré lens array

[0079] The moiré effect refers to the noticeably coarser gratings produced by the superposition of regular, finer gratings. The resulting pattern, resembling a pattern from interference, is a special case of aliasing caused by undersampling. In signal analysis, aliasing occurs when the signal being sampled contains frequency components higher than half the sampling frequency. In image processing and computer graphics, aliasing occurs when an image is sampled, resulting in patterns not present in the original image. A moiré lens array is a special case of an Alvarez lens array.

[0080] "Single component"

[0081] A single-unit component refers to a component made from a single part. A typical example of such a component is a single-pixel array, where the array is made from a single part, and the array's μ-LEDs are fabricated together on a carrier.

[0082] "Optical mode"

[0083] A mode is a description of a wave's specific time-static properties. The wave is described as a sum of different modes. These modes differ in their spatial distribution of intensity. The shape of a mode is determined by the boundary conditions of wave propagation. Analysis based on vibration modes can be applied to both standing waves and continuous waves. For electromagnetic waves such as light, lasers, and radio waves, the following types of modes are distinguished: TEM (transverse electromagnetic) mode, TE (transverse electric) or H (magnetic) mode, TM (transverse magnetic) or E (electric) mode. TEM (transverse electromagnetic) mode: Both the electric and magnetic fields are always perpendicular to the direction of propagation. This mode can only propagate when there are two isolated conductors (equipotential surfaces) in a coaxial cable or when there are no electrical conductors in a gas laser or optical waveguide. TE or H mode: Only the electric field component is perpendicular to the direction of propagation, while the magnetic field component points in the direction of propagation. TM or E mode: Only the magnetic field component is perpendicular to the direction of propagation, while the electric field component points in the direction of propagation.

[0084] "Optoelectronic components"

[0085] An optoelectronic component is a semiconductor substrate that generates light through recombination of charge carriers during operation, and then emits light. The emitted light can range from infrared to ultraviolet, with the wavelength depending on various parameters, the material system used, and the doping. Optoelectronic components are also known as light-emitting diodes (LEDs).

[0086] For the purposes of this disclosure, the terms optoelectronic component and light-emitting component are used synonymously. Therefore, in terms of its geometry, a μ-LED (see related description) is a specific type of optoelectronic component. In displays, optoelectronic components are typically monolithic or single components placed on a matrix.

[0087] "Passive matrix backplane" or "passive matrix carrier substrate"

[0088] A passive matrix display is a matrix display in which individual pixels are passively controlled (without additional electronic components for each pixel). The light-emitting diodes (LEDs) of the display can be controlled by the circuitry of an integrated circuit (IC). In contrast, a screen with active pixels controlled by transistors is called an active matrix display. A passive matrix carrier substrate is part of and supports the passive matrix display.

[0089] "Photonic crystal" or "photonic structure"

[0090] A photonic structure can be a photonic crystal, a quasi-periodic, or a deterministic aperiodic photonic structure. A photonic structure generates a band structure for photons through periodic variations in the optical refractive index. This band structure can have a band gap within a specific frequency range. This means that photons cannot propagate through the photonic structure in all spatial directions. In particular, propagation parallel to the surface is generally blocked, but propagation perpendicular to the surface is possible. In this way, the photonic structure or photonic crystal determines propagation in a specific direction. It blocks or reduces the radiation along one direction and thus produces a radiation or a beam of radiation, directed as needed to a spatial region or emission region provided for this purpose.

[0091] Photonic crystals are photonic structures that appear or are generated in transparent solids. Photonic crystals are not necessarily crystals; their name comes from the diffraction and reflection effects of X-rays in crystals, due to their lattice constant. The structural size is equal to or greater than one-quarter of the photon's wavelength, meaning they range from 1 μm to several μm. They are generated using classical photolithography or through self-organizing processes.

[0092] Alternatively, similar or identical properties of photonic crystals can also be produced with aperiodic but still ordered structures. Such structures are in particular quasi-periodic or well-defined aperiodic structures. For example, this could be a helical arrangement of photons.

[0093] In particular, the so-called two-dimensional photonic crystal is mentioned here by way of example, which has a periodic variation of optical refractive index in two spatial directions that are perpendicular to each other, especially in two spatial directions that are parallel to the light emitting surface and perpendicular to each other.

[0094] However, one-dimensional photonic structures, particularly one-dimensional photonic crystals, also exist. One-dimensional photonic crystals exhibit a periodic change in refractive index along a single direction. This direction can extend parallel to the light exit surface. The one-dimensional structure allows beam shaping to occur in a first spatial direction. In a photonic structure, the photonic effect can be achieved in just a few cycles. The photonic structure can be designed, for example, to ensure that electromagnetic radiation is at least approximately collimated relative to the first spatial direction. Therefore, a collimated beam can be generated at least relative to the first spatial direction.

[0095] "Pixel"

[0096] The individual color values ​​of a digital photodiode pattern, and the surface elements required to record or display these color values ​​in an image sensor or screen with photodiode control, are called pixels, image points, image cells, or image dots. Therefore, a pixel is a positionable element in a display device and has at least one light-emitting device. Pixels have a definite size, and adjacent pixels are separated by a defined spacing or pixel space. In displays, especially μ displays, three (or several with added redundancy) sub-pixels of different colors are typically combined into one pixel.

[0097] "planar array"

[0098] A planar array is a substantially flat surface. It is typically smooth and has no protruding structures. Generally, surface roughness is undesirable and does not provide the desired functionality. A planar array is, for example, a monolithic planar array with multiple optoelectronic components.

[0099] Pulse Width Modulation

[0100] Pulse Width Modulation (PWM) is a type of modulation used to control components, particularly μ-LEDs. A PWM signal controls a switch configured to turn on and off the current flowing through the corresponding μ-LED, thus causing the μ-LED to light up or not. When using PWM, the output provides a square wave signal with a fixed frequency f. During each cycle T (= 1 / f), the relative amount of on-time compared to the off-time determines the brightness of the light emitted by the μ-LED. The longer the on-time, the brighter the light.

[0101] "Quantum trap"

[0102] A quantum well is understood as a potential line in a strip structure within one or more semiconductor materials, which restricts the degree of freedom of a particle to move in one spatial dimension (typically the z-direction). Thus, a charge carrier can only occupy a planar region (the xy-plane). The width of the quantum well determines the quantum mechanical states that the particle can adopt, resulting in the formation of energy levels (sub-bands), meaning the particle can only have discrete (potential) values.

[0103] "complex"

[0104] There is generally a distinction between radiative and nonradiative recombination. The latter produces a photon that can leave the component. Nonradiative recombination results in the generation of acoustic quanta, which heat the component. The ratio of radiative to nonradiative recombination is an important parameter that depends on the component size, among other factors. Typically, the smaller the component, the smaller the ratio, thus increasing nonradiative recombination relative to radiative recombination.

[0105] Refresh time

[0106] The refresh time is the time after which units such as displays must be rewritten to prevent information loss or premature refresh by external factors.

[0107] "Rohchip" or "light-emitting element"

[0108] A light emitter, or virgin chip, is a semiconductor structure fabricated on a wafer and then separated from it. This semiconductor structure is adapted to generate light after electrical contact during operation. Therefore, in this context, a virgin chip is a semiconductor structure containing active layers for generating light. Virgin chips are typically separated after contact, but can also be further processed in array form.

[0109] "Slot antenna"

[0110] A slot antenna is a special type of antenna in which, instead of surrounding the metallic structure with air (as a non-conductor) in space, an interruption is provided in the metallic structure (e.g., a metal plate, waveguide, etc.). This interruption causes the reflection of electromagnetic waves, the wavelength of which depends on the geometry of the interruption. Typically, the interruption follows the dipole principle, but theoretically it can have any other geometry. Therefore, a slot antenna comprises a metallic structure with a cavity resonator whose length is on the order of the visible light wavelength. The metallic structure can be arranged in or surrounded by an insulating material. The metallic structure is typically grounded to establish a certain potential.

[0111] Field of view

[0112] The field of view (FOV) refers to the area within the field of view of an optical device, solar sensor, camera's image surface (film or recording sensor), or perspective display where events or changes can be perceived and recorded. The field of view is specifically the area that a person can see without moving their eyes. Regarding augmented reality and prominent objects placed in front of the eyes, the field of view includes the area specified as multiple angles of view during stable eye fixation.

[0113] "Subpixel"

[0114] A subpixel describes the internal structure of a pixel. Generally, the term "subpixel" is associated with a higher resolution than that expected from a single pixel. A pixel can also contain several smaller subpixels, each emitting a different color. The overall color impression of a pixel is produced by the mixing of the individual subpixels. Therefore, a subpixel is the smallest locatable unit in a display device. Similarly, a subpixel has a specific size, smaller than the size of the pixel to which it belongs.

[0115] Vertical LED

[0116] Compared to horizontal LEDs, vertical LEDs have electrical connections on both the front and back sides. One of the two sides also forms a light-emitting surface. Therefore, a vertical LED has contacts formed on two opposing main surface sides. Consequently, a conductive yet transparent material must be deposited to ensure electrical contact while allowing light to pass through.

[0117] Virtual Reality

[0118] Virtual reality (VR) refers to the representation and simultaneous perception of reality and its physical properties in a real-time, computer-generated, interactive virtual environment. Virtual reality can replace the operator's real environment with a completely simulated environment.

[0119] The following sections will introduce various aspects of the μ-LED semiconductor structure. This includes the structural and material systems used for light emission. However, these aspects also involve key processing points.

[0120] In the field of augmented reality, and in automotive displays or other display devices with μ-LEDs, a fundamental aspect is that adjacent μ-LEDs in the device are also spaced apart as μ displays or μ arrays, making it impossible for the human eye to distinguish or identify individual μ-LEDs in such a device. Specifically, individual rows or columns of μ-LEDs arranged row by row or column by column cannot be distinguished or identified by the human eye. Therefore, the distance between μ-LEDs, or the pixel density and pixel pitch of the μ-LED array, should also be adjusted accordingly based on the distance between the observer and the μ-LED array, so that the observer's eye cannot distinguish individual μ-LEDs in the μ-LED array within the appropriate application.

[0121] Compared to arrays with organic LEDs (OLEDs) and liquid crystal displays (LCDs), μ-LED arrays have lower energy consumption and up to 10 6 Cd / m 2 The advantages of high brightness. Furthermore, μ-LED arrays can achieve extremely high pixel densities of up to 5000 pixels per inch (PPI) and nanosecond-level refresh rates when applied in displays. In addition, compared to OLED and LCD, μ-LED arrays have a very long lifespan and excellent stability in resisting environmental influences. Moreover, using μ-LED arrays allows for the adaptation of contrast range and / or resolution values ​​to desired values, such as application-specific adaptation.

[0122] Furthermore, arrays composed of μ-LEDs allow the light-emitting areas formed by the μ-LEDs to be adapted to fit desired shapes. This means that the application is not limited to ordinary displays, and μ-LED arrays can also be used in the automotive field, for example, using curved surfaces as displays or lighting devices. This area can be used to display information as well as a simpler light-emitting area for illumination or lighting.

[0123] One aspect involves the generation of different colors in a monolithic display. In a monolithic μ-LED array, each individual pixel can each contain, for example, a μ-LED that emits blue light, and each μ-LED can also have a converter material to partially or completely convert the blue light into secondary light, which, together with the blue primary light, produces mixed light, such as white light. Monolithic μ-LED arrays enable high brightness in the emitting area and are therefore advantageously used in automotive lamps, such as as a light source for automotive headlights.

[0124] Conversely, non-monolithic microdisplays or μ-LED arrays allow for the arrangement of other components, such as electronic components for operating the μ-LEDs, or sensors or detectors, using the gaps between adjacent pixels or μ-LEDs. Non-monolithic μ-LED arrays can be advantageously used, for example, in displays and displays with integrated sensors, particularly touchscreens, as well as for operating elements.

[0125] If the length of the rod is reduced, a so-called μ-pillar is obtained. It is constructed as a pillar and also contains an active layer extending along the longitudinal axis on its surface, thus radiating light in virtually all directions during operation. This type of μ-pillar can be generated multiple times on a carrier through self-organization or orientation-dependent crystal growth. The very small structure makes it possible to fabricate μ-LEDs, particularly for microdisplays, where only the epitaxial process parameters need to be changed. The spatial dimensions of μ-pillar displays of this type range from several μm to nanometers and include nanometers.

[0126] Since the light generated by the μ-pillar radiates in virtually all spatial directions, the proportion of light radiated directly upwards is very small due to its small footprint. Therefore, it can be proposed that the μ-pillar be surrounded by one of the reflective structures disclosed below. The μ-pillar is arranged in a cavity, wherein the walls of the cavity are inclined and designed to be reflective. Similarly, in some aspects, the covering electrode disclosed below can be provided.

[0127] Another feasible approach is described below. This is based on the principle of separating the μ pillars and then aligning and contacting them with the substrate. In this way, horizontally aligned μ pillars are created, with each pillar forming a sub-pixel.

[0128] According to a first aspect, an electronic component, particularly a μ-LED, is proposed, wherein a μ-pillar extending substantially parallel to the carrier is connected to the carrier. For this purpose, the μ-pillar has an elongated core with a first dopant, wherein the core is covered on the outside by a layer sequence from a first longitudinal end to a second longitudinal end without a layer sequence. The layer sequence also includes an active layer, which in some respects may include a quantum well structure, etc. Additionally, special doping or other measures as disclosed in this application can be used to confine the current to a low-defect region of the active layer. The μ-pillar is electrically and mechanically connected to a first contact region of the carrier at the first longitudinal end via the layer sequence and a first contact, and electrically and mechanically connected to a second contact region of the carrier at the second longitudinal end via the core and a second contact. Finally, the layer sequence is electrically isolated from the second contact by means of a mask. Thus, the μ-pillar is configured to be elongated and substantially parallel to the carrier. Although this increases space overhead, this construction still allows for high light yield with low current.

[0129] In a method for manufacturing such electronic components and electrically connected μ-LEDs on a carrier, a μ pillar is formed in a first step, which may contact at a first end and a second end, wherein the ends respectively contact different doped layers. This formation can be achieved by epitaxial material deposition in necessary steps. Thus, the μ pillar has an elongated core with a first dopant, wherein the core grows outward from a first longitudinal end to one or more layer sequences, particularly epitaxially, from a first longitudinal end to a second longitudinal end without a layer sequence.

[0130] The μ-pillars produced in this manner are then arranged substantially parallel to the carrier. At their first longitudinal end, a layer sequence having first contacts is electrically and mechanically connected to a first contact area of ​​the carrier. At the second longitudinal end, the core is electrically and mechanically connected to a second contact area of ​​the carrier via second contacts. Here, the layer sequence is electrically insulated from the second contacts by an insulating layer.

[0131] The fabrication of μ-pillars offers high flexibility, allowing their light emission to be tuned to a desired wavelength range or wavelength. In some aspects, the geometry of the μ-pillars is designed for one of a specific wavelength of light. Besides variations in length or diameter, the geometry can also vary in thickness across different layers. μ-pillars can be fabricated with different diameters, emitting light at different wavelengths during operation. Quantum wells can be provided within the active layer. μ-pillars can be designed, for example, as polyhedra, prisms, pyramids, or wedges along their longitudinal axis. Their cross-section can have four or six corners. In some aspects, μ-pillars can be covered with additional transducer material, or in a further processed state, to convert the emitted light.

[0132] If the μ-pillars are parallel to the carrier along their longitudinal axis, a reflective layer may need to be applied between the carrier and the μ-pillars in some respects. In this case, reference should be made to the statements in other sections where the carrier has a reflector structure surrounding the μ-LEDs, so that light from the μ-LEDs arranged inside is deflected by the reflector structure. Such a reflector structure can also be arranged around multiple sets or each μ-pillar disposed on the carrier.

[0133] On one hand, three μ pillars forming a group are arranged in parallel on a carrier and connected to the contact area of ​​the carrier electrically and mechanically. Each μ pillar can be designed to emit red, green, or blue light. Therefore, these form pixels. Several such arrangements can be provided in rows and columns to form a μ display. As mentioned above, the diameters of the μ pillars used for red, green, and blue light can be different. The dimensions of the μ pillars are therefore different. In the case of multiple pixels, the arrangement of the μ pillars can reduce periodic visual artifacts.

[0134] Several aspects relate to the fabrication and generation of contacts. Therefore, first contacts, particularly p-contacts, can be realized in various ways on the first longitudinal end of the corresponding μ-pillar away from the insulating layer. This includes epitaxial growth, particularly by means of a seed layer photostructured via oxygen plasma etching. Contacts can also be formed by sputtering. In some aspects, at least one contact plane is formed on the first contact as a contact surface of the first contact region carrying the first contact. Second contacts are generated in a similar manner. Attached Figure Description

[0135] The following sections use various design schemes and examples to illustrate some of the aspects mentioned above and summarized in more detail.

[0136] Figure 1A The diagram illustrates some requirements for a so-called μ display or microdisplay device in terms of various dimensions of field of view and pixel spacing in a μ display; Figure 1B A diagram showing the spatial distribution of rod and cone cells in the human eye; Figure 1C A diagram showing the perceptual abilities of the human eye with assigned projection areas; Figure 1D A graph showing the sensitivity of rod and cone cells at different wavelengths is presented; Figure 2A The diagram illustrates some requirements for microdisplays of various sizes in terms of the field of view and collimation of pixels in a μ display; Figure 2B An exemplary design of a pixel array is shown to illustrate... Figure 1A and Figure 2A The parameters represented in the text; Figure 3AA graph showing the required number of pixels depends on the number of fields of view for a given resolution; Figure 4 An embodiment of a μ column as a raw material for manufacturing optoelectronic components, particularly μ-LEDs, is shown; Figure 5A An embodiment of a μ-LED having a μ-pillar structure oriented horizontally relative to a carrier is shown; Figure 5B Another embodiment is shown, wherein contact is achieved on the bottom side of the μ-pillar; Figures 6 to 15 An embodiment of a method for manufacturing a set of three μ-LEDs according to the proposed principles is shown, wherein the μ-LEDs are horizontally oriented and in contact with a carrier; Figure 16 Another embodiment of a horizontally oriented μ-column is shown in longitudinal section, according to some aspects; Figure 17 Another embodiment of the proposed group, which has three μ-LEDs and on which a converter layer is arranged, is shown, according to some of the proposed aspects; Figure 18 Another embodiment of the assembly with three horizontally oriented μ pillars and a reflective layer on the carrier is shown; Figure 19A A top view of a pixel device with three horizontally oriented μ pillars is shown, wherein the μ pillars are adapted to emit light with different wavelengths; Figure 19B A side view of the design scheme from the previous figure is shown; Figure 20 Another embodiment of some proposed aspects of a group of μ pillars with three orientations is shown in cross-section, wherein the μ pillars each form a μ-LED in the top view; Figure 21 Another embodiment of the proposed group is shown, which has three μ-pillars in cross-section, the μ-pillars being designed to emit light of different wavelengths due to their different geometries; Figure 22 An embodiment of a set of three proposed μ columns is shown in a stereoscopic view as an electron microscope image; Figure 23 A diagram illustrating the emission wavelengths of embodiments of the three proposed groups of μ pillars is shown; Figure 24 Another illustration shows a cross-section of an embodiment of the proposed group of three μ pillars, which together form a pixel. Detailed Implementation

[0137] Augmented reality is largely created by a dedicated display that overlays images onto reality. This display can be placed directly in the user's line of sight, i.e., directly in front of them. Alternatively, beam deflection elements can be used to direct light from the display toward the user's eyes.

[0138] In both cases, a display can be implemented, and the user can wear glasses or other visual augmentation devices as part of the device. Google's™ Glasses is an example of such a visual augmentation device, allowing users to overlay certain information about objects in the real world. With Google™ Glasses, the information is displayed on a small screen in front of the glasses. In this respect, the appearance of this add-on device is a key feature of the glasses, combining technological functionality with the design aspects of wearing glasses. Simultaneously, users need glasses that don't have such bulky or easily damaged devices to provide augmented reality functionality. Therefore, one concept is that the glasses themselves become a display or at least one screen, with information projected onto or into a projector.

[0139] In this type of situation, the user's field of view is limited to the size of the glasses. Therefore, the area on which augmented reality can be projected is approximately the size of the glasses lenses. The same but different information can be projected onto or onto both lenses of a pair of glasses.

[0140] In other words, the image experienced by a user while wearing augmented reality glasses should have a resolution that creates a seamless impression, so that the user doesn't perceive augmented reality as a pixelated object or a low-resolution element. Straight bevels, arrows, or similar elements appear as staircase-like outlines at low resolutions, which is distracting for the user.

[0141] To achieve an ideal visual impression, two display parameters are considered important, as they influence the visual impression for a given or known human eye. One is the pixel size itself, the geometry and dimensions of a single pixel, or the area of ​​three subpixels representing that pixel. The second parameter is the pixel pitch, the distance between two adjacent pixels or subpixels, which varies depending on the context. Sometimes, pixel pitch is also referred to as the space between pixels. Larger pixel gaps can be detected by the user and perceived as gaps between pixels, potentially leading to what is known as the "flying screen effect." Therefore, the gap should not exceed a certain limit.

[0142] The maximum angular resolution of the human eye is typically between 0.02 and 0.03 arcminutes, roughly equivalent to 1.2 to 1.8 arcminutes per line. This results in a pixel pitch of 0.6-0.9 arcminutes. Some current mobile phone displays have approximately 400 pixels per inch, resulting in a viewing angle of approximately 2.9° at a distance of 25 cm from the user's eyes, or approximately 70 pixels per degree. Therefore, the distance between two pixels in such a display is within the range of maximum angular resolution. Furthermore, the pixel size itself is approximately 56 μm.

[0143] Figure 1A The pixel spacing is shown, that is, the distance between two adjacent pixels that depends on the field of view. In this respect, the field of view is the extension of the observable world seen at a given moment. This is because human vision is defined as the angle of view in degrees during a stable fixation of the eye.

[0144] In particular, the forward horizontal curvature of the binocular visual field is slightly higher than 210°, while the vertical curvature of the human visual field is approximately 135°. However, the range of visual ability is not uniform across the entire visual field and may vary from person to person.

[0145] Human binocular vision covers approximately 114° horizontally (peripheral vision) and approximately 90° vertically. The remaining degrees on both sides do not constitute binocular vision, but can be considered part of the field of view.

[0146] Furthermore, color vision and the ability to perceive shape and motion further limit the horizontal and vertical fields of vision. The rods and cones responsible for color vision are unevenly distributed.

[0147] This viewpoint Figures 1B to 1D This was explained in more detail. In the central visual domain, that is, directly in front of the eyes, as required by augmented reality applications, and partly in the automotive field, the eye's sensitivity is very high in terms of spatial resolution and color perception.

[0148] Figure 1B The spatial density of cones and rods per square millimeter is shown, which is related to the angle of the central concave region. Figure 1C The wavelength-dependent color sensitivity of cones and rods is described. In the central region of the fovea, increased cone density (L, S, and M) leads to better color perception. Sensitivity begins to decrease at a distance of approximately 25° around the fovea, as the density of visual cells decreases. Near the edges, color perception decreases further, but contrast vision through rods remains over a wider angular range. Overall, this creates a radially symmetrical visual pattern for the eye, rather than a Cartesian one. Therefore, high resolution of all primary colors is necessary, especially at the center. At the edges, working with an emitter adapted to the spectral sensitivity of rods may suffice (maximum sensitivity 498 nm, see...). Figure 1D And the sensitivity of the eyes).

[0149] Figure 1C The graph of angular resolution A relative to the angular deviation α from the optical axis of the eye illustrates the different perceptual abilities of the human eye. It can be seen that the highest angular resolution A exists within the interval of + / - 2.5° angular deviation α, where the fovea 7 is arranged on the retina 19 with a diameter of 1.5 mm. Furthermore, the location of the blind spot 22 on the retina 19 is plotted, which appears in the region of the optic disc 23, with an angular deviation α of approximately 15°.

[0150] The eye can compensate for this non-constant density, and it can also compensate for so-called blind spots through minute eye movements. This change in the direction or focus of the gaze can be counteracted through appropriate optical systems and eye tracking.

[0151] In addition, even when wearing glasses, the field of vision is further limited; for example, the field of vision of each lens can be within approximately 80°.

[0152] Figure 1A The pixel pitch on the Y-axis, measured in μm, defines the distance between two adjacent pixels. Different curves, C1 to C7, define the diagonal dimensions of the corresponding displays, ranging from 5mm to approximately 35mm. For example, curve C1 corresponds to a display with a diagonal dimension of 5mm, meaning a side length of approximately 2.25mm. For a field of view of approximately 80°, the pixel pitch of a display with a 5mm diagonal dimension is within the range of 1μm. For larger displays, such as those using curve C7 and a 35mm diagonal dimension, the same field of view can be achieved with a pixel pitch of approximately 5μm.

[0153] However, Figure 1A The curves in the diagram illustrate that a larger field of view is preferred for augmented reality applications, while very high pixel density and small pixel pitch are required to avoid the well-known screen-flying effect. We can now calculate the pixel size for a given number of pixels, a given field of view, and a given diagonal size for a μ display.

[0154] Equation 1 shows the relationship between pixel size D, pixel pitch pp, number of pixels N, and display edge length d. The distance r between two adjacent pixels, calculated from their respective centers, is given by the following equation.

[0155] r = d / 2 + pp + d / 2.

[0156] D = d / N-pp (1)

[0157] N = d / (D + pp)

[0158] Assuming the distance between the monitor (e.g., glasses) and the eye is 2.54 cm (1 inch), then for the roughly estimated 1 arcminute angular resolution above, the distance r between two adjacent pixels is...

[0159] r = tan(1 / 60°) × 30mm

[0160] r = 8.7μm

[0161] Therefore, pixel size is less than 10 μm, especially when a certain space is required between two different pixels. Using the distance r between two pixels and a display with a size of 15 mm × 10 mm, 1720 × 1150 pixels can be arranged on the surface.

[0162] Figure 2B An arrangement with a carrier 21 is shown, on which a plurality of pixels 20 and 20a to 20c are arranged. Pixels 20 arranged adjacent to each other have a pixel pitch pp, while pixels 20a to 20c are placed on the carrier 21 with a larger pixel pitch pp. The distance between two pixels is given by the sum of the pixel pitch and half the size of each adjacent pixel. Each pixel 20 is configured such that its illumination characteristics, or emission vector 22, are substantially perpendicular to the emission surface of the corresponding LED.

[0163] The angle between the vertical axis on the emitting surface of the LED and the beam vector is defined as the collimation angle. In the example of emission vector 22, the collimation angle of LED 20 is approximately zero. LED 20 emits collinear light and does not expand significantly.

[0164] Conversely, the collimation angle of the emission vector 23 of LED pixels 20a to 20c is very large, and is in the range of approximately 45°. As a result, a portion of the light emitted by LED 20a overlaps with the emission of the adjacent LED 20b.

[0165] The emission of LEDs 20a to 20c partially overlaps, resulting in the superposition of their respective light emissions. If the LEDs emit different colors of light, the result will be a mixture or combination of colors. A similar effect occurs between high-contrast areas, i.e., when LED 20a is dark while LED 20b emits some kind of light. Due to the overlap, the contrast is reduced, and the information at each individual location corresponding to the pixel position is also reduced.

[0166] For displays with a small distance from the user's eyes, such as those mentioned above, a large collimation angle can be quite annoying due to the aforementioned effects and other drawbacks. Users can perceive a large collimation angle and may experience a slight difference in the color of depicted objects, a blurriness, or reduced contrast.

[0167] in this regard, Figure 2A This illustrates the collimation angle in degrees relative to the field of view in degrees, which is independent of a specific display size. For smaller display sizes, such as those in curve C1 (approximately 5mm diagonally), the collimation angle increases significantly depending on the field of view.

[0168] As monitor sizes increase, the requirements for collimation change dramatically. Therefore, even with large monitor geometries, as shown by curve C7, the collimation angle reaches approximately 10° within a 100° field of view. In other words, the collimation requirements increase for larger monitors and larger fields of view. In such monitors, the light emitted from the pixels must be highly collimated to avoid or reduce the aforementioned effects. Therefore, when providing users with monitors that offer large fields of view, even if the monitor's geometry is relatively large, robust collimation capabilities are necessary.

[0169] Based on the above charts and equations, it can be deduced that as the geometry and field of view of a display increase, the requirements regarding pixel pitch and collimation become increasingly challenging. As Equation 1 shows, the size of a display increases dramatically with the number of pixels. Conversely, a large field of view requires a large number of pixels to achieve sufficient resolution and avoid screen flickering or other interference effects.

[0170] Figure 3A The diagram illustrates the number of pixels required to achieve an angular resolution of 1.3 armes. For a field of view of approximately 80°, the number of pixels exceeds 5 million. It can be quickly estimated that the pixel size for QHD resolution is far less than 10μm, even with a display size of 15mm × 10mm. In total, an augmented reality display with resolutions in the HD range (i.e., 1080p) requires a total of 2,073,600 pixels. This would cover a field of view of approximately 50°. The number of pixels arranged in a 10 × 10mm display with a pixel spacing of 1μm would result in a pixel size of approximately 4μm.

[0171] The above considerations make it clear that the challenges in terms of resolution, collimation, and field of view suitable for augmented reality applications are considerable. Therefore, the technical implementation of such displays also places very high demands on them.

[0172] Traditionally used technologies were designed for manufacturing displays with LED edge lengths in the range of 100 μm or even longer. However, they cannot automatically scale to the 70 μm and below dimensions required here. Pixel sizes of a few μm and distances of a few μm or even smaller, closer to the order of magnitude of the generated light wavelength, require new processing technologies.

[0173] Furthermore, new challenges have emerged in light collimation and guidance. For example, optical lenses that can be easily structured into larger LEDs and calculated using classical optics cannot be directly scaled down to such small sizes without using Maxwell's equations. In addition, it is nearly impossible to manufacture small lenses without large errors or deviations. In some variants, quantum effects affect the behavior of pixels of these sizes and must be taken into account. Tolerance requirements in the production or transmission techniques of pixels on auxiliary carriers or matrix structures are becoming increasingly stringent. Pixels must also be contactable and individually controllable. Conventional circuitry has space requirements that, in some cases, exceed the pixel area, creating placement and space issues.

[0174] Therefore, new designs for controlling and accessing pixels of this size may be entirely different from traditional technologies. Finally, a key focus is on the power consumption of such displays and controls. Low power consumption is particularly desirable for mobile applications.

[0175] In summary, many designs suitable for larger pixel sizes require extensive modifications before successful scaling down. While a design suitable for producing 200 μm LEDs can be easily scaled up to 2000 μm LEDs, scaling down to 20 μm is much more difficult. Many documents and literature disclosing such designs do not account for the various effects and increased requirements of extremely small sizes, and therefore are not directly applicable to or limited to pixel sizes significantly larger than 70 μm.

[0176] The following sections present various aspects of the structure and fabrication of μ-LED semiconductors, including processing, optical coupling output and light guidance, display, and control. These are suitable for designing displays with pixel sizes of 70 μm and below. Some designs are specifically designed for the production, optical coupling output, and control of μ-LEDs with edge lengths less than 20 μm, particularly less than 10 μm. It goes without saying that the designs presented here regarding these aspects can and should be combined with each other. For example, this relates to the design of μ-LEDs with designs for producing coupled output light. Specifically, μ-LEDs implemented, for example, by methods to avoid edge defects or by current conduction or current contraction, can provide optical coupling output structures based on photonic crystal structures. Special control can also be implemented for displays with variable pixel sizes. Light guidance with piezoelectric mirrors can be implemented in μ-LED displays based on slot antennas or conventional monolithic pixel matrices.

[0177] In some of the design options and aspects described below, additional examples of various design options or combinations of their aspects are indicated. These are intended to clearly show that those skilled in the art can combine the aspects, design options, or parts thereof with each other. Some applications require specially modified designs, while others have lower technical requirements. Automotive applications and displays, for example, typically have larger pixel edge lengths due to the greater distance from the user. In particular, there are classic pixel applications or virtual reality applications, in addition to augmented reality applications. In the context of this disclosure, this is also clearly desirable for realizing μ-LED displays with pixel edge lengths below 70 μm.

[0178] Figure 4 An embodiment of a separately manufactured μ-pillar M is shown. It serves as the basis for producing the proposed electronic component with a large number of horizontally oriented μ-pillars.

[0179] The μ-pillar comprises a core 1, which is partially encapsulated by a layer sequence 3. The layer sequence 3 is formed from the inside out through a first layer 5, an active layer 7, and a second layer 9. The core 1 comprises n-type doped GaN. The first layer 5 may also have n-type doped GaN, but with a different doping concentration. The active layer 7 has one or more quantum wells or quantum wells with InGaN. Charge carriers recombine and emit light in the active layer 7. The second layer 9 is deposited on the active layer 7 and comprises p-type doped GaN.

[0180] μ pillars were formed on a sapphire substrate S, on which an optional growth layer 2 made of n-type doped GaN was grown. A structured mask 4b made of SiO2 was applied.

[0181] The cross-section of the μ-pillar M is a regular hexagon. The diameter decreases at its tip and ends in a pyramidal shape. The active layer 7 thus extends around the core and essentially from the mask layer 4b to the tip. The p-type doped GaS layer also completely surrounds the core and the active layer 7.

[0182] The emission wavelength is determined by the shape and geometry, particularly the diameter of the μ-pillars, and the material system and / or doping used for the active layer. The dimensions of the μ-pillars, especially the height, are in the range of a few μm, for example, less than 20 μm or in the range of 5 μm. The diameter is also a few μm, for example, 2 μm. In some aspects, the height-to-diameter ratio is in the range of 1:1 to 4:1. After production, the μ-pillars are removed from the growth substrate 2 and further processed.

[0183] Figure 5A An embodiment of a μ-pillar M is shown, which is fixed on a carrier and electrically connected, thus forming a pixel or sub-pixel. Figure 5AThe cross-section of the μ-pillar along section AA is shown again in the upper right. The cross-section of the μ-pillar is hexagonal with equal angles and edges. A layer sequence 3 from the inside to the outside is shown, wherein this layer sequence is further surrounded on the outside by a current spreading layer 28. The current spreading layer is advantageously transparent and extends from the tip of the μ-pillar to the insulating layer 4b.

[0184] The μ-pillar M is now placed longitudinally and substantially parallel to the carrier B. A current-spreading layer 28 or a p-type doped layer 9 is connected to a first contact 13 at its first longitudinal end 12. The first contact extends along the lower half of the pyramid or apex and from the apex 12 into the longitudinally extending region. A portion of the contact is also connected to the upper side of the tip, thus forming a cap and partially encapsulating the tip of the μ-pillar. The contact 13 is then applied to a contact region 17, which connects to the carrier B and any electrical structures present therein. The contact region 17 extends across the surface of the carrier B, thereby slightly spaced the μ-pillar from the surface of the carrier.

[0185] Core 1 is connected to contact 15 at its other rear end 14. Contact 15 does not create a short circuit due to the residue of the insulating mask layer 4a and is electrically insulated from layers 19 or 28. The height of contact 15 extends approximately to the upper part of the insulating layer 4a. This contact is also electrically and mechanically connected to contact area 19. Contact areas 17 and 19 have substantially the same height, thus aligning the μ-pillar parallel to the surface orientation of the carrier. In this example, the space between the carrier B and the μ-pillar is empty, i.e., not filled with reflective material. However, as further explained below, it is advantageous to create a reflector structure below and around the μ-pillar arranged in this manner.

[0186] Figure 5B It is an alternative design solution and is... Figure 5A Further details are provided. In this design, the μ-pillar is in direct contact with the surface of carrier B. For this contact, a contact area 17' is provided, designed with a large area, which simplifies positioning. In another design, the contact area 17' may also protrude slightly beyond the surface of carrier B, thus positioning the μ-pillar slightly above. Contact 15 connects to contact element 19'. Additionally, this figure shows another substrate IC-S, which houses multiple driver circuits, wires, and other components. Another pair of contacts 38 and 39, also designed with a large area, connect to the wires and circuits. For example, contact area 38 leads to ground potential 41, and contact area 39 leads to driver circuit 40, which is schematically shown here. Adhesive 37 connects the two carriers to each other. The large contact area simplifies the process of overlapping the carriers.

[0187] According to Figure 5BIn another design, the μ-pillar can also be located directly on the base carrier B. In this design, the p-type doped layer 9 or the current spreading layer is directly connected along the longitudinal side to the first contact region 17' on the surface of the carrier B. The second contact region 19' is disposed in the carrier B insulated from it and is electrically and mechanically connected to the contact 15. This can be omitted, except for simpler manufacturing. Figure 8 and Figure 9 In this step, a larger contact area 17' can be provided. This makes alignment and placement easier. The contact area 17' includes a reflective conductive layer. Alternatively, a reflective structure can be provided around the μ-LED. This forms a box around the μ-LED, where the surfaces or spaces between them can be filled with converter material.

[0188] Figures 6 to 16 An embodiment of a method for manufacturing a set of optoelectronic components consisting of three μ pillars is shown. Figure 6 Three μ pillars M are shown, arranged adjacent to each other and extending perpendicularly from the growth substrate S. These μ pillars M are formed by means of an optional growth layer 2 with a first doping. A structured mask 4b is applied to the surface of the growth substrate 2. In the exposed locations, elongated cores 1 are formed perpendicularly from the growth layer 2, wherein the cores 1 have the same material as the growth layer 2. The growth process produces... Figures 4 to 6 The core gradually tapers to a point. Then, layer sequence 3 is deposited on the core through multiple steps. First, layer 5 with the same doping type is deposited on the core. An active layer 7 is grown on top of this, comprising multiple quantum wells. A p-type doped layer 9 is adjacent to the active layer 7. Furthermore, a current-diffusing layer is applied to the p-type doped layer to distribute the injected charge carriers across the entire region of the p-type doped layer 9. Of course, p-type and n-type doping can be interchanged. In these examples, layer sequence 3 is generated as epitaxially as possible.

[0189] Figure 6 Further method steps for fabricating the proposed optoelectronic component are shown. A first contact 13 is formed for a group of three μ-pillars. For this purpose, photoresist 11 is applied to the surfaces of the μ-pillars and the current spreading layer. The longitudinal ends 12 with sharp points are then exposed by O2 plasma etching, and conductive transparent contacts are applied to the tips over a large area. ITO is suitable for this contact 13. Figure 6 As shown, the contact does not extend over the entire tip, but only over the upper region.

[0190] exist Figure 7 Alternative design solutions are visible. These can be generated in the following way, based on... Figure 6The first contact 13 serves as a seed layer, upon which contact material is then electroplated or sputtered. Thus, contact 13 has at least one contact plane, on which the first contact area 17 of the carrier B can be mechanically and electrically connected in a simple manner. The contact planes for contacting the first and second contact areas 17 and 19 extend parallel to the longitudinal axis of the μ-pillar M.

[0191] It is advantageous for the first contact point 13 to be formed as a cube or parallelepiped because the part obtained in this way does not show a strong change in its diameter, but rather essentially forms a body with a hexagonal base or another polyhedron.

[0192] Figures 8 to 10 Further method steps for manufacturing the proposed optoelectronic component are shown. In this method step, a set of three μ pillars M, specifically a group of three μ pillars M, is transported from the growth substrate S to the film 23 by means of flip-chip technology. Figure 8 This forms the starting point for the method. Although only three columns are shown, a large number of such μ columns can be provided in columns and rows.

[0193] In the first step, according to Figure 9 The μ-pillars are surrounded by a connecting layer 21, particularly a thermoplastic connecting layer 21. This extends from the contact 12 to the mask layer 4b. If necessary, and not shown here, the connecting layer 21 is removed except for the first contact, resulting in a flat surface. The first longitudinal end 12 and the contact 13 are temporarily positioned on the substitute carrier E. In this step, the assembly of the μ-pillars M is transported onto the substitute carrier along with the growth layer 2 and the sapphire substrate.

[0194] exist Figure 10 In this process, the alternative carrier E has been removed, so that the μ pillars M are now held together by the connecting layer 21. Additionally, the growth substrate S and layer 2 are removed. Only a portion of the mask layer remains on the μ pillars as an insulating layer. A contact 15 is applied to the surface of the now exposed core. It forms an electrical contact with the core and extends over a portion of the insulating layer. The second contact 15 can be fabricated by electroplating or sputtering, respectively.

[0195] Contact 15 has at least two contact planes substantially parallel to the longitudinal sides of the μ-pillar, to which the second contact area 19 of the carrier B can be easily mechanically and electrically connected, and on the other hand, the μ-pillar M can be fixed. Figure 11 On the foil 23 shown. Like contact 13, the second contact 15 can also be designed as a cube or cuboid.

[0196] After the foil 23, on which the contact 15 is mechanically fixed, is applied, the μ column can be further transferred, stored, or processed. Contact with the foil 23 can be achieved by adhesive force, but it can also be achieved by glue, etc. The first longitudinal end 12 remains unchanged. Figure 12 In the next step shown, the connecting layer 21 is completely removed. As a result, the μ pillars are now "suspended" on foil 23, thus allowing for easy transfer to a carrier or other processing. Figure 13 In the alternative design shown, only the connecting layer 21 is partially removed, so that the μ pillar is still slightly wrapped by it.

[0197] according to Figure 13 The three contacting μ pillars fixed to foil 23 have been separated, so that the connecting layer 21 is only partially removed. The pillars themselves are still encased within it, but are no longer in contact with each other. This means that the μ pillars are also isolated here. The end of the corresponding first contact 13 facing away from the mask 4b is still not covered.

[0198] Figure 14 The subsequent steps of the proposed method for manufacturing the proposed optoelectronic component are shown in cross-section. The groups of individual μ-pillars (M) are separated from foil 23 and then lifted by an assembly beam. For this purpose, foil 23 is placed on a rotating roller and guided alongside it, where the deflection of the corresponding groups simplifies the separation. The assembly beam can remove multiple (e.g., hundreds) μ-pillars at a time. In this example, the different μ-pillars are placed back-to-back, i.e., onto the drawing plane. Figure 13 The foil in the drawing also extends into or outside the drawing plane, thus showing a side view of the foil in the drawing.

[0199] Figure 15 The method steps are illustrated, in which three adjacent μ-pillars are conveyed onto a carrier M and secured. The μ-pillars, lifted from foil 23, are placed parallel to contact areas 17 and 19. Specifically, contact 13 is bonded to area 17, and contact 15 is bonded to area 19. This creates an electrical and mechanical connection. Welding or other fastening processes can be used instead of bonding. The support surfaces of contacts 13 and 15 are designed such that they lie flat on contact surfaces 17 or 19, respectively. This reduces or prevents tilting. Depending on the process technology and workload used, up to several hundred μ-pillars can be conveyed simultaneously.

[0200] Figure 16Another embodiment of the assembly arranged in this manner is shown from the side. A μ-pillar M is shown, lying flat and parallel to the carrier B and connected to the first contact 13 and the second contact 15. The μ-pillar M has a core 1, a first layer 5, an active layer 7, a second layer 9, and an insulating layer 4a. Below the μ-pillar and currently invisible, a reflective layer is applied to or within the surface of the carrier B. Additionally, a reflector structure 25 is formed around the μ-pillar. It has sloping walls similar to those shown in another figure. This allows light emitted from the side to be deflected upwards. As described in this disclosure, the sidewalls may be metallic. Alternatively, the reflector structure may be made of TiO2 in a silicone matrix, which reflects the light generated by the active layer 7 away from the carrier B.

[0201] Figure 17 and Figure 18 A further embodiment with three optoelectronic components arranged adjacent to each other is shown in a perspective view. As described below, the μ-pillars can be designed to produce light of the same wavelength or different wavelengths.

[0202] Figure 17 Three μ pillars with the same structure, parallel to carrier B, are shown. Each μ pillar has a first contact 13 and a second contact 15 connected to carrier B. All μ pillars M are also oriented parallel to each other. Two pillars are additionally encapsulated in a converter layer C1 or C2, which converts blue light into red or green light. The surface of carrier B is covered with a reflective material. With the aid of reflective layer 25, additional light can be emitted from carrier B, thus increasing light output.

[0203] On the contrary, according to Figure 18 In this embodiment, carrier B is completely covered by the dark absorption layer 27. This improves contrast.

[0204] Figure 19A A top view of a pixel device with three horizontally arranged μ-pillars adapted to emit light of different wavelengths is shown. The three μ-pillars R, G, and B exhibit different geometries, each having the same length but varying widths. To produce uniform light intensity for the user, the lengths of the μ-pillars can also differ. The three μ-pillars R, G, and B are connected to corresponding ports on a carrier 27 via first contacts 15. Second contacts are applied to the tips of each μ-pillar. They contact a common metal structure 28. This metal structure is surrounding and has a reflective, sloping surface similar to that of the embodiment shown in the figure. Thus, light is reflected upwards. Furthermore, a photonic structure 30 is applied to the surface, extending over the entire cavity formed by the surrounding metal structure. It terminates at the top of the surrounding structure 28, but may extend beyond this range depending on the application.

[0205] In this article, Figure 19BThis is a side view of the design scheme from the previous figure. The photonic structure 30 is not located on the individual surfaces of the μ-pillars, but is instead slightly separated by a transparent dielectric layer. The dielectric layer extends at least on the surfaces of the μ-pillars facing the main radiation direction, but it can also fill cavities and thus form a plane of the photonic structure 30. The latter can be placed on the surface, epitaxially, or otherwise applied. The height of the photonic structure is appropriately chosen.

[0206] Figure 20 A top-down view shows something similar to Figure 17 The design scheme is as follows. The corresponding μ-pillar M is electrically and mechanically connected to the contact area on the carrier B via its first contact 13 and second contact 15. Here, a red, green, and blue light source, for example, used in an indicator or display, is shown. The three μ-pillars M have the same construction and emit, for example, blue light. By means of a converter material 29, the blue light can be converted into red or green light. Figure 20 In the image, the left μ-pillar M without converter material emits blue light, the middle μ-pillar M covered by the first converter material 29 emits red light, and the right μ-pillar M covered by the second converter material emits green light. Here, the first and second contact regions 17 and 19 of the carrier B are also connected to additional contact surfaces for adhesion. Figure 20 In the image, two bond lines are shown above and below.

[0207] Figure 21 Another embodiment of the proposed group with three μ pillars is shown in cross-section. In this embodiment, the diameter of the grown structure is changed. This change alters the color coordinates of the μ pillars. Therefore, it is possible to generate multiple μ pillars M on the wafer that emit different colors in a single epitaxial step. In the case of selective epitaxy, the diameter of the μ pillar M is changed in one step, that is, without altering the overall growth parameters.

[0208] On the growth substrate S, for each specific wavelength of light emission, three μ pillars M are generated, their spatial expansion coordinated with this. They are essentially the same length, but their diameters differ due to epitaxial growth. This leads to variations in diameter, and the structures may result in different colors.

[0209] Figure 22 Images of these μ-pillars with varying sizes are shown in electron microscopy. The μ-pillars are regular hexagons with slightly angled and tapered upper edges. This corresponds to the pointed tip in the design aspect shown above. Depending on the design scheme, the length of the μ-pillar corresponds to its diameter. In the left image only, the length is approximately twice the diameter of the μ-pillar. The μ-pillars grow on a flat but insulating surface, on which a portion is retained as germ cells. Variations in geometry produce different colors, with the smallest diameter μ-pillar exhibiting the largest wavelength. Figure 22 A red transmitter is shown on the left, a green transmitter in the middle, and a blue transmitter on the right.

[0210] Therefore, the geometry shown leads to a relationship between the diameter and wavelength for a given length. As the diameter decreases, the wavelength of light increases. Figure 23 A diagram illustrating emission wavelengths ranging from 450 nm to approximately 650 nm with different diameters is shown. This relationship is also repeated in... Figure 24 As shown in the diagram, the diameter emitting red light is approximately half the diameter of the emitted light. Within a small wavelength range, there is a linear relationship between the diameter of the μ-pillar and the wavelength of the emitted light. Besides the hexagon shown here as the surface geometry, other geometries can be grown. In the case of small diameters, the hexagon is not actually very clear due to process limitations.

[0211] This method allows for the generation of μ-pillars with greater surface radiation and higher luminous flux. For this purpose, the μ-pillars are arranged on the carrier with lugs along their longitudinal direction. Therefore, the longitudinal axis of the μ-pillars is substantially parallel to the longitudinal axis. In the embodiment shown here, the μ-pillars are slightly spaced from the surface of the carrier by slightly protruding contact areas.

[0212] In the following sections, various devices and apparatuses, as well as methods for their manufacture, processing, and operation, are again listed as examples. The following items illustrate aspects and implementations of the proposed principles and designs that can be combined in various ways. Such combinations are not limited to those given below: 70. A μ-LED device having - At least one μ-pillar arranged along the carrier, wherein the μ-pillar forms an elongated core along the longitudinal axis, the core having a first doping, and the core being coated outwardly from a layer sequence at a first longitudinal end to a layer sequence at a free second longitudinal end, wherein, - At least the μ column is electrically and mechanically connected to the first contact area of ​​the carrier at the first longitudinal end through a layer sequence and a first contact, and electrically and mechanically connected to the second contact area of ​​the carrier at the second longitudinal end through a core and a second contact, wherein the layer sequence is electrically isolated from the second contact through an insulating layer.

[0213] 71. The μ-LED device according to item 70, wherein the μ column has a matching geometry for emitting light of a defined wavelength and is particularly designed as at least one polyhedron, particularly as a prism or parallelepiped, wherein the first longitudinal end terminates particularly as a pyramid, a truncated pyramid, an obelisk, or a wedge.

[0214] 72. The μ-LED device according to any one of the foregoing items, Its features are, A μ column has a spatial extension that is consistent with its wavelength, and in particular a defined diameter that is perpendicular to its longitudinal axis, in order to emit light of a specific wavelength.

[0215] 73. The μ-LED device according to any one of the foregoing items, Its features are, μ-pillars are covered with a converter material that is compatible with the wavelength of light they emit.

[0216] 74. The electronic component according to any one of the foregoing items, Its features are, Forming a reflective layer on a μ-pillar and / or support, particularly a TiO2 layer in a silicone matrix; or A dark, particularly black, layer is formed on the μ column and / or the support.

[0217] 75. The μ-LED device according to any one of the foregoing items, Its features are, Transparent layers, particularly ITO sheaths, are formed on μ columns and / or supports.

[0218] 76. The μ-LED device according to any one of the foregoing items, Its features are, Shells are produced on μ columns and / or carriers, particularly as castables.

[0219] 77. A pixel element having three μ-LED devices according to any one of the preceding items, wherein

[0220] These three components are electrically and mechanically connected to the contact area of ​​the carrier in parallel with and / or parallel to each other, wherein the three electronic components are designed to emit light of at least one wavelength.

[0221] 78. The pixel element according to the aforementioned item, wherein each of the three μ-LED devices is designed to emit light at different frequencies.

[0222] 79. The pixel element according to any one of the preceding items, wherein the first longitudinal ends of the μ pillars of the three μ-LED devices are connected to a common port.

[0223] 80. The pixel element according to any one of the preceding items, wherein a reflective surrounding structure is formed around three μ-LED devices, particularly a surrounding structure based on the features of any one of the following items.

[0224] 81. The pixel element according to item 80, wherein the reflective surround structure forms a port for a contact area at the first or second longitudinal end of the μ column of the three μ-LED devices.

[0225] 82. The pixel element according to any one of the preceding items further includes a photonic structure, particularly a photonic structure according to any one of the following items, arranged above the μ-LED device.

[0226] 83. A method for producing a μ-LED device, comprising the following steps: - Generate μ pillars arranged along the carrier, the μ pillars forming elongated cores along the longitudinal axis, the elongated cores having a first doping, and the cores being coated outward from a layer sequence at a first longitudinal end to a free layer sequence at a second longitudinal end, wherein... - The μ column is connected to the first contact area of ​​the carrier at the first longitudinal end by a layer sequence and a first contact point. - The μ column is connected to the second contact area of ​​the carrier at the second longitudinal end via the core and the second contact, wherein the layer sequence is electrically isolated from the second contact by an insulating layer.

[0227] 84. According to the method described in item 83, the step of generating the μ column includes: - Generate a layer sequence from the core outwards as a first layer with first doping, an active layer, and a second layer with second doping.

[0228] 85. The method described according to item 83 or 84 further includes: - Generate a set, in particular three, structurally identical μ-pillars, which decrease in size along the direction of the first longitudinal end in a cross section perpendicular to the longitudinal axis and / or terminate at the tip, edge, or plane of the first longitudinal end.

[0229] 86. The method according to any one of the foregoing items, further comprising: - In particular, by means of selective epitaxy, a set, especially three, of μ pillars with different diameters and / or different geometries are generated on the growth substrate, so that they are designed to emit light of different wavelengths.

[0230] 87. The method according to any one of the foregoing items includes: - On the first longitudinal end of the corresponding μ pillar away from the insulating layer, in particular epitaxially, in particular by means of a seed layer photostructured by oxygen plasma etching and / or in particular by electroplating or sputtering, a first transparent contact, in particular a p-contact, is formed, wherein at least one contact plane is formed on the first contact.

[0231] 88. According to the method described in item 87, - The first longitudinal end is connected to the insulating layer by a connecting layer, particularly a thermoplastic connecting layer, surrounding the set of μ pillars, wherein the first longitudinal end temporarily abuts against a substitute carrier; - Remove the growth substrate.

[0232] 89. The method according to any one of the foregoing items, further comprising:

[0233] - A second transparent contact, particularly an n-contact, is formed on the second longitudinal end of the corresponding μ-pillar facing the insulating layer, particularly by electroplating or sputtering, wherein at least two contact planes are formed on the second contact.

[0234] 90. The procedure according to any one of the foregoing items, Its features are, The group of μ-pillars is fed onto the foil. The second contact of the corresponding μ column is fixed to the foil, especially by utilizing the contact plane.

[0235] 91. The method according to item 90 further includes: The group of μ columns is separated, wherein at least part of the connecting layer is removed.

[0236] 93. The method described according to item 90 or 91, further comprising:

[0237] The foils of the three separate μ columns in particular are stripped and electrically and mechanically connected to the first and second contact areas of the carrier, parallel to each other and / or parallel to the carrier, through their first and second contacts, particularly through the contact plane.

[0238] 94. According to the method described in Project 93, Simultaneously stripping and simultaneously electrically and mechanically connecting approximately 500 to 1500 sets of μ columns.

Claims

1. A miniature light-emitting diode device, comprising: At least one micro-column arranged along the carrier, wherein, The micropillars form elongated cores along the longitudinal axis, the cores having a first doping, and the cores are coated outwards from a layer sequence at the first longitudinal end to a layer sequence at the free second longitudinal end, wherein... The micropillar is electrically and mechanically connected to the first contact area of ​​the carrier at least at its first longitudinal end via a layer sequence and a first contact, and the micropillar is electrically and mechanically connected to the second contact area of ​​the carrier at its second longitudinal end via the core and a second contact, wherein the layer sequence is electrically isolated from the second contact via an insulating layer.

2. The miniature light-emitting diode device according to claim 1, wherein, The micropillar has a geometry that is compatible with the light in order to emit light of a specific wavelength, and the micropillar is specifically designed as at least one polyhedron, specifically as a prism or parallelepiped, wherein the first longitudinal end specifically terminates as a pyramid, a truncated pyramid, an obelisk, or a wedge.

3. The miniature light-emitting diode device according to claim 1, characterized in that, The micropillar has a spatial extension that is coordinated with the light, and in particular a defined diameter perpendicular to the longitudinal axis, in order to emit light of a defined wavelength.

4. The miniature light-emitting diode device according to claim 1, characterized in that, The micropillars are covered with a converter material that is compatible with the light in order to emit light of a specific wavelength.

5. The miniature light-emitting diode device according to claim 1, characterized in that, A reflective layer is formed on the micropillars and / or carrier, particularly a TiO2 layer in a silicone matrix; or A dark, particularly black, layer is formed on the micropillars and / or carrier.

6. The miniature light-emitting diode device according to claim 1, wherein, A transparent layer, particularly an ITO sheath, is formed on the micropillars and / or carrier.

7. The miniature light-emitting diode device according to claim 1, characterized in that, Shells are formed on the micropillars and / or carriers, particularly as shells as castables.

8. A pixel element having three micro light-emitting diode devices according to claim 1, wherein, Three components are electrically and mechanically connected to the contact area of ​​the carrier in parallel with and / or parallel to each other, wherein the electronic component is designed to emit light of at least one wavelength.

9. The pixel element according to claim 8, wherein, Each of the three micro LED devices is designed to emit light, and the emitted light has a different frequency.

10. The pixel element according to claim 8, wherein, The first longitudinal end of the micropillar of the three micro-LED devices is connected to a common port.

11. The pixel element according to claim 8, wherein, A reflective surround structure is formed around the three said micro light-emitting diode devices, particularly a surround structure based on the features of any one of the following claims.

12. The pixel element according to claim 11, wherein, The reflective surround structure forms a port for the contact area at the first or second longitudinal end of the micropillar of the three micro-LED devices.

13. The pixel element of claim 8 further comprises a photonic structure, particularly a photonic structure characterized according to any one of the following claims, said photonic structure being disposed on a micro-light-emitting diode device.

14. A method for manufacturing a miniature light-emitting diode device, comprising the following steps: Micropillars are generated along a carrier, wherein the micropillars form an elongated core along a longitudinal axis, the core having a first doping, and the core is coated outwardly from a layer sequence at a first longitudinal end to a free second longitudinal end, wherein... The micropillars are connected to the first contact area of ​​the carrier at the first longitudinal end through a layer sequence and a first contact point. The micropillar is connected to the second contact area of ​​the carrier at the second longitudinal end via the core and the second contact, wherein the layer sequence is electrically isolated from the second contact by an insulating layer.

15. The method according to claim 14, wherein, The steps for generating micropillars include: generating a layer sequence from the core outwards, comprising a first layer with first doping, an active layer, and a second layer with second doping.

16. The method according to claim 14 or 15, further comprising: Generate a set, particularly three, of structurally identical micropillars, which decrease in size along a direction toward the first longitudinal end in a cross section perpendicular to the longitudinal axis and / or terminate at the first longitudinal end with a tip, edge, or plane.

17. The method of claim 14, further comprising: In particular, by means of selective epitaxy, a set, especially three, of micropillars with different diameters and / or different geometries are generated at the growth substrate, such that the micropillars are designed to emit light of different wavelengths.

18. The method of claim 14, further comprising: On the first longitudinal end of the corresponding micropillar away from the insulating layer, a first transparent contact, particularly a p-contact, is formed epitaxially, particularly by means of a seed layer photostructured by oxygen plasma etching, and / or particularly by electroplating or sputtering, wherein at least one contact plane is formed on the first contact.

19. The method according to claim 18, wherein, The assembly of micropillars is surrounded from the first longitudinal end to the insulating layer by a connecting layer, particularly a thermoplastic connecting layer, wherein the first longitudinal end temporarily abuts against a substitute carrier; Remove the growth substrate.

20. The method of claim 14, further comprising: In particular, by electroplating or sputtering, a second transparent contact, especially an n-contact, is formed on the second longitudinal end of the corresponding μ-pillar facing the insulating layer, wherein at least two contact planes are formed, especially on the second contact.

21. The method of claim 14, wherein the assembly of micropillars is conveyed onto a foil. The second contact of the corresponding micro-pillar is fixed to the foil, in particular by utilizing the contact plane.

22. The method of claim 21, further comprising: The micropillars are separated, wherein at least part of the connecting layer is removed.

23. The method according to claim 21 or 22, further comprising: The foil is peeled off in groups, especially three separate micropillars, and the micropillars are electrically and mechanically connected to the first and second contact areas of the carrier, parallel to each other and / or parallel to the carrier, through the first and second contacts of the micropillars, especially through the contact plane.

24. The method of claim 23, simultaneously stripping and simultaneously electrically and mechanically connecting approximately 500 to 1500 sets of micropillars.

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