LED Rod Structure With Protective Layer for Etchant Lift-Off
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Solution Overview
Problem
Inorganic light-emitting diodes (ILEDs) face damage to their outer surfaces and electrodes during the chemical lift-off process due to etchant exposure, leading to rough surfaces and potential contact or emission failures in display devices.
Innovation Solution
A method of fabricating light-emitting elements involves forming a rod structure with a semiconductor rod surrounded by a protective organic layer that does not react with etchants, allowing for safe separation from the substrate without damaging the semiconductor rods, using materials like polymethyl methacrylate (PMMA), photoresist (PR), or poly-(3,4-ethylenedioxy thiophene)polystyrene sulfonate (PEDOT:PSS) for the protective layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If chemical lift-off method is used to separate semiconductor rods from substrate, then separation is achieved, but outer circumferential surfaces and electrodes of rods are damaged by etchant
Solution Approach 1:
A protective layer is introduced as an intermediary between the etchant and the semiconductor rod surfaces. This protective layer selectively resists the etchant, allowing the separation layer to be removed while preserving the outer circumferential surfaces and electrodes of the semiconductor rods from chemical damage
Solution Approach 2:
The protective layer is formed on the outer circumferential surfaces and electrodes of the semiconductor rods before the chemical lift-off process begins. This preliminary protective coating prevents etchant exposure to vulnerable surfaces during the subsequent separation process
2Reliability
If protective layer is formed on semiconductor rods, then surface damage is prevented, but additional fabrication steps are required
Solution Approach 1:
The protective layer serves multiple functions: it protects the semiconductor rod surfaces and electrodes from etchant damage during separation, and it can also serve as a base layer for subsequent electrode formation or encapsulation processes. This multi-functionality reduces the need for additional separate protective measures
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
This approach prevents damage to the semiconductor rods during separation, resulting in smooth outer surfaces and minimized contact or emission failures, enhancing the reliability of light-emitting elements in display devices.
Implementation Method 1
the separation layer may be etched away by an etchant for separation
Implementation Method 2
dissolving the organic material of the rod protecting layer in a solvent
Implementation Method 3
removing the organic material dissolved in the solvent may comprise thermally treating, and thereby evaporating, the organic material
Data Source
AI summary
Provided are a light-emitting diode structure and a light-emitting diode manufacturing method. The light-emitting diode manufacturing method comprises the operations of:preparing a lower substrate, which includes a substrate and a separation layer formed on the substrate, and preparing at least one semiconductor rod, which is formed on the separation layer, forming a rod structure, which includes a rod protecting layer formed on the separation layer to surround the at least one semiconductor rod and an auxiliary layer formed on at least part of the rod protecting layer and separating the rod structure from the lower substrate by removing the separation layer, and separating the at least one semiconductor rod from the rod structure.