Leti, a research institute of CEA Tech, announced a scalable technology for fabricating GaN microLED displays for applications ranging from smart watches to TVs. The approach fabricates elementary units of all-in-one red, green, blue (RGB) microLEDs on a CMOS driving circuit, and transfers the devices to a simple receiving substrate. The units are fabricated with a full semiconductor, wafer-scale approach.
The CMOS-based approach provides higher brightness and higher resolution microLEDs and is well suited for very large TVs, promising exceptional image quality and better energy efficiency than existing liquid crystal display (LCD) and organic light-emitting diode (OLED) technologies. Faster electronics are required to power millions of pixels in a fixed-frame time in microLED displays, but existing driving display technology, known as thin-film transistor (TFT) active matrix, cannot provide the necessary current and speed.
CEA-Leti's approach fabricates CMOS-driven GaN microLED displays with a simplified transfer process that eliminates the use of the TFT backplane. RGB microLEDs are stacked directly onto a micro-CMOS circuit, and each unit is transferred onto a simple receiving substrate. Then, the RGB microLEDs and the backplane are fabricated on a single semiconductor line. The process increases power and driving speed while avoiding several steps needed with current technology to make electrical and mechanical contacts between microLEDs and the receiving substrates.
Find out more at www.leti-cea.com.