Micro-LED Dielectric Opening Design for Leakage Reduction
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Solution Overview
Problem
Micro-light-emitting diodes (micro-LEDs) face efficiency reductions due to non-radiative recombination, uneven current density, and increased leakage currents as they miniaturize, along with manufacturing challenges such as decreased yield rates and electrostatic sensitivity.
Innovation Solution
A micro-LED design featuring a first dielectric layer with an opening that exposes a semiconductor layer, ensuring charge carriers do not spread to the side surface, thereby reducing non-radiative recombination, enhancing current density uniformity, and minimizing leakage currents, while allowing for continued miniaturization with improved yield rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If miniaturization of LEDs proceeds to microscale, then size is reduced, but non-radiative recombination increases due to charge carriers spreading to side surface
Solution Approach 1:
A dielectric layer is introduced as an intermediary between the electrode and the semiconductor layer. This dielectric layer with controlled opening prevents charge carriers from spreading to the side surface, thereby reducing non-radiative recombination while allowing the micro-LED to maintain miniaturized dimensions
Solution Approach 2:
The patent controls the distance parameter (first shortest distance) between the opening edge and side surface to be greater than or equal to 1 μm. By adjusting this geometric parameter, charge carrier spreading is limited, reducing non-radiative recombination losses while maintaining small device size
2Length of moving object
If miniaturization of LEDs proceeds to microscale, then size is reduced, but current density becomes low and uneven within emitting area
Solution Approach 1:
The dielectric layer with a strategically positioned opening creates local quality variation in the current path. The opening is positioned to allow current to flow through specific regions while blocking other paths, ensuring uniform current density distribution across the emitting area despite the miniaturized scale
3Length of moving object
If miniaturization of LEDs proceeds to microscale, then size is reduced, but leakage currents increase due to lattice defects
Solution Approach 1:
The dielectric layer acts as an intermediary barrier that prevents charge carriers from reaching lattice defects on the side surface. This isolation reduces leakage currents generated by defects while allowing the micro-LED to maintain its miniaturized dimensions
Solution Approach 2:
The patent extracts or removes the problematic interaction between charge carriers and side surface defects by introducing the dielectric layer with opening, thereby eliminating the source of leakage currents while preserving the miniaturized structure
4Length of moving object
If miniaturization of LEDs proceeds to microscale, then size is reduced, but yield rate decreases due to process variation tolerance
Solution Approach 1:
By establishing a minimum distance parameter (≥1 μm) between the opening and side surface, the patent creates a tolerance buffer that accommodates process variations. This parameter control ensures consistent performance and higher yield rates even as devices are miniaturized
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design increases micro-LED efficiency by reducing non-radiative recombination and leakage currents, maintains high yield rates during manufacturing, and lowers electrostatic sensitivity, enabling smaller emitting areas with comparable light output to larger micro-LEDs.
Implementation Method 1
when electrons and holes recombine across the semiconductor gap, the recombination energy is emitted in the form of photons and generates light. This recombination mechanism is the so-called radiative recombination
Implementation Method 2
when electrons and holes recombine through intermediate electronic states in the semiconductor gap, then the recombination energy is emitted in the form of heat instead of photons, reducing the light emission efficiency of the LED. This recombination mechanism is the so-called non-radiative recombination
Data Source
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AI summary
A micro-light-emitting diode (micro-LED) includes a first type semiconductor layer, a second type semiconductor, a first dielectric layer, and a first electrode. The second type semiconductor layer is disposed on or above the first type semiconductor layer. The first dielectric layer is disposed on the second type semiconductor layer. The first dielectric layer has at least one opening therein to expose at least one part of the second type semiconductor layer. A first shortest distance between an edge of the opening of the first dielectric layer and a side surface of the second type semiconductor layer is greater than or equal to 1 μm. The first electrode is partially disposed on the first dielectric layer and is electrically coupled with the exposed part of the second type semiconductor layer through the opening of the first dielectric layer.