Yield Enhancement for Micro-LED Production

Automatically optimizing fabrication processes like etching or deposition using machine learning and statistical inference to guide process development. The technique involves using models to simulate the fabrication process, characterizing the uncertainty in the model predictions, and then using an acquisition function to select optimal process parameters for the next experiment. The function balances exploration to further constrain model uncertainty with exploitation to drive closer to target specifications. By iteratively selecting parameters, optimal sets can be found even with multiple competing specifications and many adjustable parameters.

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HEMT driven MicroLED integrated backplane and manufacturing method for high resolution and large size MicroLED displays that avoids the challenges of transfer bonding and mass transfer methods. The method involves growing a HEMT epitaxial structure along with the RGB MicroLED chips on the same substrate. This allows direct integration of the HEMT and MicroLEDs at the epitaxial growth stage, eliminating the need for separate wafer processing and transfer steps. The integrated HEMT-MicroLED structure is then transferred to the display backplane. This provides a compact, efficient and reliable MicroLED display solution with improved yield and performance compared to separate wafer processing and transfer techniques.

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A method for monitoring annealing uniformity of semiconductor chips to improve yield by detecting voltage in the annealed chips instead of depositing thick metal layers. The method involves forming P-type contacts on epitaxial layers, annealing, then forming N-type contacts and annealing again. Voltage is measured in the N-type contact areas to monitor annealing uniformity across the chips. This reduces steps compared to depositing thick metal layers for voltage measurement.

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Method to sort and process sapphire substrate wafers after cutting to reduce waste and improve yield. The method involves classifying the cut wafers based on warpage and bending. Wafers with higher defects undergo annealing and grinding to improve quality. Then, the wafers are sorted again and polished using parameters specific to their defect level. This targeted processing reduces loss compared to uniform polishing.

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Automatically identifying and correcting deviations in chip manufacturing processes like glue coating to improve yield and reliability. The method involves decomposing the target glue thickness into multiple processes with single thicknesses, monitoring those processes in real-time, identifying deviations using a neural network, and adjusting parameters for the next process based on the deviation impact. This iterative correction improves glue uniformity and reduces defects. The network analyzes factors like platform speed, glue dispense rate, and amount to determine deviation impact on photoresist uniformity.

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Using AI to detect defects in LED wafers during production to improve yield by catching defects earlier in the process. The method involves capturing images of the wafers at various stages using machine vision, identifying defects using an AI module that learns defect characteristics, processing the images to mark areas with and without defects, calculating yield based on the marked areas, and displaying the results. This allows identifying areas prone to defects and making process adjustments to prevent them.

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Monitoring chip annealing uniformity in semiconductor manufacturing to improve yield and performance. The method involves annealing contacts and the light-emitting layer separately on multiple chips in multiple wafers, then voltage testing the electrode areas on all the chips to monitor annealing uniformity across the wafers. This provides more comprehensive annealing monitoring compared to just testing a few points.

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Method to measure flaws in multi-environment Micro LED epitaxial wafers for improving overall yield and quality by detecting and addressing defects in different environmental conditions. The method involves processing the wafers, fixing them in a jig, and moving them between temperature, humidity, and gas chambers for comparison measurements. By subjecting the same wafer to variations in environment, it allows observing how flaws change and integrally detecting defects under continuous environment changes.

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Detecting defects in epitaxial wafers during production to reduce waste and improve yield. The method involves monitoring heating power data during epitaxial growth and looking for fluctuations. If fluctuations are detected, it indicates potential pin mark defects in the wafer. This allows stopping the production process to avoid producing more defective wafers.

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Optimizing semiconductor manufacturing process parameters to improve critical dimension quality and yield. The method involves establishing a comprehensive model based on process parameters and quality parameters, and using it to find the optimal process parameter values for critical dimensions. The model can predict quality based on process parameters, allowing selection of the best values for optimized critical dimensions. By optimizing process parameters based on critical quality attributes, it reduces wafer loss and improves yield.

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Method to analyze and improve LED epitaxial wafer quality by reverse engineering the effect of patterned substrates. The method involves step-by-step etching and inspection of the epitaxial layers to connect substrate defects with layer anomalies. Macroscopic and microscopic analysis is done on the epitaxial surface and etched surfaces to identify abnormalities. By sequentially etching and inspecting layers, the correlation between substrate features and epitaxial defects is established. This enables understanding of substrate impact on epitaxy and optimizing processes to reduce abnormal products.

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A micro-LED display device that can meet high-resolution requirements and has a high micro-LED product yield for manufacturing. The device has a circuit substrate with micro-LED units on one side and a metal conductive layer on the other. The conductive layer contacts the epitaxial layer of the micro-LEDs and has light conversion regions. A light conversion layer in some regions converts emitted light. Light-shielding structures on the epitaxial layer cover some areas. The metal layer is thicker than the epitaxial layer.

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Reducing non-radiative recombination of micro LED to prevent the non-radiative recombination occurring on the etched sidewalls of the micro LEDs. The reduction includes supplying at least one etched LED epitaxial wafer, laying a first ALD to the etched LED epitaxial wafer in a first temperature range; performing a second ALD to the etched LED epitaxial wafer etched by the first ALD in a second temperature range, and forming a passivation layer on the etched sidewalls of the mesas later being the micro LEDs.

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Method for monitoring semiconductor wafer fabrication processes using optical inspection to improve yield management and defect analysis. The method involves using machine learning to extract features from optical inspection images, calculate monitoring metrics like defect counts, and determine separability metrics that quantify how well classified defects meet inspection criteria. By analyzing separability trends, it can distinguish between process variations within specification versus true defects. This allows isolating and monitoring the impact of variable defect capture rates and counts on wafer inspection results due to process variations, which improves process control and yield analysis.

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Manufacturing process for an ultra-high-resolution Micro-LED micro-display screen with a simple process and few pixel defects. The process includes: providing an LED epitaxial wafer; forming isolation columns on the wafer to divide it into chip regions; placing conductive solders in the chip regions; performing a first CMP process to remove the conductive solders outside the chip regions; forming electrodes and LED light-emitting structures on the wafer; performing a second CMP process to remove upper parts of the electrodes and LED structures outside the chip regions; and removing the isolation columns to separate the chips. The process enables producing micro-displays with ultra-high pixel density and resolution suitable for AR/VR headsets.

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MicroLED array with improved efficiency and yield for displays and lighting applications. The microLED array is formed by growing a monolithic microLED stack on a relaxed lattice constant substrate. The stack has layers with different compositions to introduce strain. This strain is relieved by deforming the top layer during processing. This reduces defects and improves efficiency compared to conventional microLEDs where the active layer is strained. The relaxed microLED array can be formed in a single process by selectively removing and heat treating layers.

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A production control method for LED devices that improves yield by optimizing process parameters and environmental conditions. The method involves collecting production step parameters and environmental indicators during LED manufacturing, stopping production after a set number of devices, inspecting them, and adjusting step parameters and environment if quality requirements are not met. This iterative optimization based on real-time data helps control factors that affect LED quality and yield.

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A method for manufacturing micro-LED display panels that simplifies the mass transfer of millions of micro-LEDs by bonding them directly to a backplane substrate through a conductive layer on the LED surface. The method starts with growing the LED epitaxial layers on a base substrate that can then be peeled off by laser lift-off. The peeled LEDs are then bonded to a backplane using a conductive layer. This eliminates the need for separate transfer steps and improves yield compared to conventional methods.

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Optimizing semiconductor device manufacturing processes using probabilistic yield optimization. The method involves controlling lithography processes like exposure dosing, focus, and alignment by dynamically balancing multiple conflicting control objectives based on probabilities of achieving each objective. It acquires process data, determines corrections, and adjusts them based on the probabilities of meeting different control objectives. This allows prioritizing objectives like maximizing yield versus minimizing residuals.

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A micro-LED display panel design allows for repairing defective pixels to improve panel yield. The driving backplane of the micro-LED display is designed with multiple spatially independent electrode pairs. The LED chips are soldered to any of the electrode pairs. If a chip in a pixel is defective, it can be desoldered and resoldered to a different electrode pair. This allows the repair of individual pixels instead of scrapping the whole panel when a single pixel is bad.

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Micro LED display module manufacturing method that improves yield by allowing replacement of defective LEDs before final assembly. The method involves pressurizing the LEDs on the substrate before curing the adhesive layer, to electrically connect them and check their operation. Defective LEDs are identified and replaced with alternatives.

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Micro-LED with improved light extraction efficiency and manufacturing yields by shaping the LED geometry to minimize losses of side-emitted light. The micro-LED has a reflective layer surrounding a tilted side surface to redirect and extract light emitted from the sidewall. This improves total light extraction compared to conventional vertical sidewall micro-LEDs. The tilted sidewall also allows more LEDs to be grown on a substrate. The micro-LED has a vertical sidewall on one side and a tilted sidewall on the other.

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Mass transfer method and apparatus for Micro LED manufacturing. The method involves designing differently shaped Micro LED chips of different colors and matching shaped transfer cavities on a vibrating transfer mold surface. When dumped and vibrated together, each color's uniquely shaped LED chips fall into corresponding cavities. This allows mass transfer of multiple colors at once, improving efficiency exponentially while ensuring high yield.

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Optimizing the edge cleaning width in semiconductor processes like chemical mechanical planarization (CMP) to improve device yield by reducing impurity particle substitution. The method involves finding the optimal edge cleaning width that minimizes failure rate by analyzing failure images. The width is determined by comparing failure proportions from different widths and selecting the lowest. This optimal width is then used for subsequent processing to reduce impurity substitution and improve yield.

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Micro LED display module with densely packed micro LEDs on a multilayer circuit board with minimal pads. This allows high-resolution displays with reduced thickness, improved yield and simplified bonding compared to individual LED encapsulation. The circuit board has top and bottom layers with pads matching orthographic projections of the micro LEDs. Internal layers between them provide routing. A flat insulating layer covers the LEDs. The pads connect to drive the LEDs which are arranged in a matrix.

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Reducing non-radiative recombination in microLEDs to improve brightness and efficiency. The method involves repairing dangling bonds and defects on the etched sidewalls of microLEDs and mesa structures using atomic layer deposition (ALD) at a lower temperature. Then, a passivation layer is deposited at a higher temperature to prevent non-radiative recombination. This repairs and protects the sidewalls to reduce defects that affect microLED performance compared to larger LEDs.

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Micro-LED chip design for efficient red light emission using a GaAs epitaxial structure with a platform to reduce cost and improve yield compared to traditional LED designs. The platform exposes the N-type window layer on one side while embedding the second electrode in a trench on the other side, with insulation to isolate it.

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Transfer method of micro LEDs to improve manufacturing efficiency of displays by replacing whole defective modules rather than individual LEDs. The method involves transferring the micro LEDs from a donor substrate to a relay substrate, cutting it into individual modules, testing them for defects, then transferring only the normal modules to the display substrate.

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A semiconductor manufacturing process and control system that improves yield by adjusting process parameters based on uncorrectable errors detected after processing. After a wafer completes a process step, its surface topography is measured. Uncorrectable errors compared to expected topography are obtained. These errors are fed back to adjust the process parameters of that step in real time for future wafers. This allows correcting issues that cause uncorrectable errors in subsequent steps. The process parameters are iteratively optimized based on detected errors to reduce yield losses.

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A method for predicting semiconductor wafer yield using process capability indices instead of electrical test data. The method involves calculating process capability indices for each step of the wafer fabrication process using statistical data. These indices represent how closely the process is following the targeted specifications. By using the process capability indices as input features to a prediction model, it aims to provide a more stable and accurate yield prediction compared to using electrical test data due to the non-linear relationship and susceptibility to noise.

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Method for manufacturing a micro LED panel using a novel process to improve yield and performance compared to conventional approaches. The method precisely calculates the number and position of micro LED chips required for each pixel region, forms those chips together on a single substrate, then transfers and fixes them all at once to the display panel. This accurate and efficient chip transfer prevents position deviations and simplifies manufacturing compared to individual transfers. The resulting micro LED panels have excellent light output performance and improved yield.

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A method for manufacturing LED chips that improves product yield by increasing light extraction efficiency. The method involves diffusing zinc onto the surface of the LED epitaxial wafer after etching, followed by removing the zinc layer. This process creates a textured surface on the LED chip that reduces total internal reflection and improves light extraction. The zinc diffusion and removal steps can be performed using standard semiconductor processing techniques.

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Micro LED display manufacturing with improved yield and reliability through a structure where the light emitting layer is bonded to a support substrate before removing the growth substrate. This reduces process tact time to reduce breakage possibility.

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Manufacturing micro LED displays with improved yield and reliability by using a sol-gel glass to fill gaps between micro LED chips on a first substrate, detaching the chips from their original substrate, and bonding a second substrate on top. This avoids the need for transfer heads or complex transfer processes.

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Dynamic adjustment of test conditions during wafer testing to improve yield and reliability. It involves running monitoring test items first before regular tests. The monitoring results are analyzed to predict wafer yield. If predicted yield is low, test parameters are tightened for regular tests. This filters more unqualified chips in wafer testing to save downstream costs and improve yield. If predicted yield is high, regular tests use default parameters.

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Micro-LED display panel architecture that improves micro-LED yield by allowing pixel repair. The driving backplane of the display panel has multiple pairs of anodes and cathodes. The anode and cathode leads are shared between pixel units. This allows replacing a defective LED by simply connecting the chip to a different anode/cathode pair, instead of replacing the entire panel.

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Integrated substrate processing platform that enables high-volume manufacturing of semiconductor devices with improved yield and throughput by reducing non-conformities and defects. The platform has integrated metrology modules and sensors that measure workpiece attributes before and after processing steps without breaking vacuum. An active interdiction control system analyzes the measurement data to detect non-conformities. It then takes corrective actions like remedial processing, adjustments, or ejection to address issues. This active interdiction prevents further processing of defective wafers and compensates for non-conformities mid-process. The integrated metrology and interdiction reduces time between issues, improves yield, and automates corrective actions.

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Micro LED chip that can emit red, green, and blue light from a single chip. The chip has multiple active layers, with one layer emitting blue light and another layer emitting green light. A phosphor layer is added to convert some of the blue or green light to red light. By using a single chip that can produce all three primary colors, the complexity, yield issues, and alignment challenges of transferring multiple colored chips are avoided, simplifying production of microLED displays.

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Micro LED display technology that aims to reduce the number of mask steps and improve manufacturing yield by using transparent variable resistance materials as electrodes. The variable resistance material is used as a transparent electrode that can be made conductive by forming a filament when a voltage greater than a threshold is applied. This allows a transparent electrode to be formed on the upper semiconductor layer of each micro LED without needing a separate mask step.

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Method for transferring micro-LEDs to a receiving substrate to enable manufacturing high-quality micro-LED displays. It involves using a laser to lift-off micro-LEDs from the original substrate and transfer them to a receiving substrate. An anisotropic conductive layer makes electrical contact with the receiving substrate pads. This avoids complications of pick-up tools and multiple transfers. The laser lift-off enables easy transfer without damaging the micro-LEDs.

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Microscale LED lighting devices with repair capabilities to improve manufacturing yield. The micro LED device has a main luminescent device and a redundant luminescent device. When the main LED is functioning, the redundant LED is electrically isolated from the circuit. But if the main LED fails, the redundant LED can be activated by connecting its electrodes to the circuit using a conductive material. This provides a repair mechanism to enable failed micro LEDs to be replaced by redundant ones.

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Micro LED lighting device with a repair mechanism to improve manufacturing yield and enable in-situ repair. The device has a redundant micro LED that can be activated if the main micro LED fails. The redundant LED has separate electrical connections that can be switched on to bypass the main LED. The repair mechanism allows the redundant LED to be activated and connected when the main LED fails, providing a backup lighting source. This allows failed micro LEDs to be repaired by switching to the redundant LED. The repair mechanism improves yield and product reliability.

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MicroLED display device manufacturing method to improve yield and reliability. The method involves providing a substrate with printed circuits, attaching microLED chips to the circuits, filling gaps with sol-gel glass, and bonding a second substrate. This avoids complex transfer heads and improves yield compared to chip transfer methods.

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A technique for manufacturing high density micro LED displays with improved yield by using a temporary substrate in the transfer process. The method involves fabricating the micro LEDs on a sacrificial silicon substrate with a lower resolution process. Then the micro LEDs are transferred en masse to the high resolution TFT substrate using a temporary transfer substrate. This allows for looser alignment tolerances in the transfer process compared to direct transfer from silicon to TFT. Finally, the temporary substrate is removed, leaving the micro LEDs on the TFT substrate.

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A light-emitting unit for displays that uses micro-LEDs and bonding pads with specially shaped pins for improved yield and uniformity. The micro-LED has a strip-like element pin with length>width and nonzero angle to the strip-like bonding pin. This allows easier alignment and welding between the pins with lower precision. The strip shape gives a larger tolerance for pin misalignment compared to point-like pins.

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Micro-LED display technology that enables low-cost high-resolution displays with improved yield and reliability. The displays use tiny inorganic LEDs transferred onto a substrate using printing techniques. The LEDs have metal contacts on one side and emit light out the other side. The metal contacts are separated by a small distance, allowing simple interconnection. By transfer printing the LEDs, they can be assembled on large-area substrates. The displays can have high pixel density and yield, and use integrated circuits to control LED sets.

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Method for process monitoring and yield management in semiconductor manufacturing that predicts final device performance based on measurements of unfinished wafers. The method involves estimating key device performance metrics like leakage current by measuring properties of intermediate layers on the wafer. This allows early detection of issues and process optimization to prevent yield loss. By projecting final performance from incomplete wafers, it provides more accurate and actionable feedback compared to isolated layer measurements.

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Automatically extracting guidance for online process control of semiconductor wafers using design data. The method involves identifying potential margins in the device design and generating information for process control based on those margins. The margins are automatically identified by querying design data for specific attributes. The process control information is used to set parameters for wafer inspection, metrology, and failure analysis. This allows guiding online process control based on design insights to improve yield and quality.

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Micro-LED display technology. More specifically, it relates to a light-emitting unit and a display device that improve yield and reduce defects in micro-LED bonding. The light-emitting unit has a specially shaped pin configuration where the element pin is longer and at an angle compared to the bonding pin. This enables easier alignment and welding of the micro-LED element pins to bonding pads. The angled, asymmetrical pin configuration allows more tolerance in pin alignment and reduces the chances of misalignment that can cause welding defects.

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Micro-LED array display manufacturing method that enables wafer level transfer of micro-LEDs to improve yield and reduce cost. The method involves temporarily bonding micro-LEDs on a donor wafer to a carrier substrate, lifting them off the donor wafer using laser irradiation, transferring them to a transfer head substrate, bonding them to a receiving display substrate, and finally removing the transfer head to leave the micro-LEDs on the display. This allows selective transfer of only good micro-LEDs, repair of defects, and use of laser-transparent substrates.

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