Micro-LED Structure Using Ion Implantation for Mesa Isolation
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Solution Overview
Problem
Conventional etching processes used in manufacturing micro-LEDs result in weak adhesion of micro-LED mesas to substrates, leading to peeling issues and damage to sidewalls, which affects the optical and electrical properties of the LED structure, especially as mesas become smaller.
Innovation Solution
The use of an ion-implanted isolation material within the semiconductor layers to electrically isolate micro-LED units without etching the epitaxy layer, enhancing adhesion and reducing physical damage by forming a highly resistive region that confines current flow within defined semiconductor layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional etching process is used to electrically isolate individual micro-LEDs, then electrical isolation is achieved, but adhesion of micro-LED mesas to substrate becomes weak causing peeling
Solution Approach 1:
The patent introduces an isolation layer as an intermediary substance between adjacent micro-LED mesas. This isolation layer is formed by selectively removing material in regions between mesas, creating physical and electrical separation without etching the mesas themselves. The isolation layer acts as a mediator that provides electrical isolation while preserving the integrity and adhesion of the micro-LED mesas to the substrate.
Solution Approach 2:
The patent extracts the isolation function from the micro-LED mesas themselves by removing material only in the regions between mesas. Instead of etching the mesas to create isolation, the process extracts and removes the intervening material to form isolation trenches or isolation layers, leaving the mesas intact and properly adhered to the substrate.
2Reliability
If conventional etching process is used to isolate micro-LED mesas, then electrical isolation is achieved, but sidewalls of micro-LED mesas are damaged affecting optical and electrical properties
Solution Approach 1:
The isolation layer serves as an intermediary that provides electrical isolation between adjacent mesas without requiring direct contact with or etching of the mesa sidewalls. By forming the isolation structure in the spaces between mesas rather than on the mesas themselves, the process avoids damaging the critical sidewall regions that determine optical and electrical performance.
Solution Approach 2:
The process extracts and removes material only from the regions between adjacent mesas, creating isolation structures that separate the mesas electrically while leaving the mesas themselves untouched. This selective extraction approach removes the harmful etching action from the mesa sidewalls while still achieving the necessary electrical isolation.
3Productivity
If micro-LED mesas are made smaller to increase pixel density, then display resolution is improved, but adhesion becomes even weaker increasing peeling risk
Solution Approach 1:
The isolation layer acts as a mediator that provides electrical separation between increasingly small adjacent mesas without requiring etching of the mesas themselves. As mesas become smaller and closer together, the isolation layer maintains necessary electrical separation while the mesas retain their full adhesion area to the substrate, preventing peeling even at high pixel densities.
Solution Approach 2:
The patent segments the semiconductor structure into distinct regions: the micro-LED mesas that remain intact and adhered to the substrate, and the isolation regions between them that are selectively removed or filled with isolation material. This segmentation allows independent optimization of mesa size for high density while maintaining adhesion through preservation of the mesa-substrate interface.
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 improves the adhesion of micro-LEDs to substrates, reduces sidewall damage, and enhances the optical and electrical properties of micro-LEDs by eliminating the need for etching processes, thereby increasing the reliability and performance of micro-LED arrays.
Implementation Method 1
The second doping type semiconductor layer includes an isolation material made through implantation
Data Source
AI summary
A LED structure includes a substrate, a bonding layer, a first doping type semiconductor layer, a multiple quantum well (MQW) layer, a second doping type semiconductor layer, a passivation layer and an electrode layer. The bonding layer is formed on the substrate, and the first doping type semiconductor layer is formed on the bonding layer. The MQW layer is formed on the first doping type semiconductor layer, and the second doping type semiconductor layer is formed on the MQW layer. The second doping type semiconductor layer includes an isolation material made through implantation, and the passivation layer is formed on the second doping type semiconductor layer. The electrode layer is formed on the passivation layer in contact with a portion of the second doping type semiconductor layer through a first opening on the passivation layer.