Sub-Micron Lithography Using InGaN Micro-LEDs: Mask-Free Fabrication of LED Arrays

摘要: The fabrication of gallium-nitride (GaN)-based light-emitting diode (LED) arrays by a direct writing technique, itself using micron-sized LEDs (micro-LEDs), is reported. CMOS-driven ultraviolet GaN-based micro-LED are used to pattern photoresist layers with feature sizes as small 500 nm. Checkerboard-type square LED array devices then fabricated such patterns based on either single pixel or multipixel writing, and implemented part completely mask-less process flow. These exemplar composed 450-nm-emitting 199 $\,\times\,$ $\mu{\rm m}^{2}$ pixels 200- m}$ pitch 520-nm-emitting 21 18 23- pitch. Fill factors 99% 71.5% achieved optical output power densities per 5 20 ${\rm W}/{\rm cm}^{2}$ at 90- 6-mA dc-injected currents, respectively.