Pixelation of GaN based Micro-LED arrays by tailoring injection energy and dose of fluorine ion implantation

Abstract

The pixelation of Micro-LED still faces intractable technological problems with the shrinkage of pixel by using conventional mesa etching processes, such as reduced luminous efficiency and tough metal interconnection. In this work, a novel pixelation strategy using fluorine (F) ion implantation with tailored injection energy and dose has been proposed and investigated through simulation and experiment. It is found that both the injection depth and spatial distribution range are determined by injection energy. The lateral spreading of the F ions could be effectively suppressed by decreasing injection energy and increasing dose while achieving equal electrical isolation. Furthermore, the uniformity of lateral spreading could be improved by introducing multi-energy injections. For verification and demonstration, Micro-LED arrays with fixed pitch and various pixel sizes were fabricated by F ion implantation, both photoluminescence and electroluminescence characteristics show that the pixel contrast and uniformity are well maintained even for the Micro-LED array with pixel size of 10 μm. For Micro-LED array with pitch and pixel sizes of 40 μm and 10 μm, the reverse leakage currents at a reverse bias voltage of −5 V is 1.45 × 10−7 A, which is lower than that formed by conventional bench top etching. The pixelation method by fluorine ion implantation with tailored injection energy and dose is expected to be able to pave the way toward high-performance Micro-LED and Nano-LED displays.