High‐Resolution 960 × 540 and 1920 × 1080 UV Micro Light‐Emitting Diode Displays with the Application of Maskless Photolithography

Herein, active matrix 370 nm ultraviolet (UV) micro light‐emitting diode (micro‐LED) displays with full high‐definition resolution of 960 × 540 and 1920 × 1080 and high pixel densities of almost 2000 and 3200 pixels per inch (PPI), respectively, are reported. A novel self‐aligned process is used to fabricate the 1920 × 1080 micro‐LED array with the inverted trapezoidal‐shape mesa, which is different from the conventional vertical mesa for the 960 × 540 micro‐LED array. In addition, the single pixels with the diameters of 8 and 5 μm on the 960 × 540 and 1920 × 1080 microarrays exhibit excellent characteristics, including the low forward voltages of 3.35 and 3.29 V at the currents of 17.4 and 4.4 μA, extremely low leakage currents of 19.5 and 9.4 pA at −10 V, and high light output powers of 150 and 71 μW at 1 mA, respectively. Through flip‐chip bonding technology, the 1920 × 1080 micro‐LED display has a higher light output power of 2.6 mW than the 960 × 540 micro‐LED display of 1.8 mW at the same driving current of 100 mA and voltage of 5 V. Both the UV micro‐LED displays demonstrate the delivery of graphic images and simple pattern‐programmable maskless photolithography on resist‐coated wafers.