Improving Display Performance of MicroLED Devices through Ion Implantation for Pixel Isolation

In recent years, GaN-based homoepitaxial microLEDs have attracted significant attention due to their superior properties, including low defect density and effective thermal management. However, mesa-structured devices encounter challenges related to sidewall effects, which can lead to non-radiative recombination and optical crosstalk, adversely affecting performance. This study explores the use of ion implantation with fluorine ions (F-) as a novel approach for pixel isolation, replacing traditional ICP etching. The ion implantation technique introduces deep defect energy levels that reduce conductivity and create high-resistance regions, effectively addressing sidewall-related issues. We fabricated microLED devices with dimensions ranging from 10×10 µm² to 100×100 µm² using 150 keV fluorine ion implantation. The electrical performance was evaluated through IV and JV measurements, revealing negligible leakage current. Notably, smaller devices exhibited higher current at the same voltage, indicating a reduction in series resistance. A more than 50% reduction in series resistance was observed for the 100×100 µm² devices compared to conventional ICP-etched structures. These findings demonstrate that ion implantation significantly enhances electrical performance and simplifies the fabrication process of GaN-based microLEDs, presenting a promising direction for future developments in microLED technology.