[Paper] Automotive OLED Display with High Mobility Top Gate IGZO TFT Backplane

Abstract

High performance IGZO TFTs with top gate structure were developed for an automotive OLED display backplane. Fabrication processes are optimized by balancing oxygen and hydrogen contents with μ-PCD method. The mobility of the IGZO TFTs reaches as high as 32 cm²/Vs with enhanced threshold voltages. We have checked the TFTs reliability under the positive bias temperature (PBT), negative bias temperature (NBT) and negative bias temperature illumination (NBTI) stress tests. As the IGZO TFTs shows slight changes of threshold voltage (V_th) within ±0.5V under PBT and NBT and even after NBTI stress tests, there is no critical deterioration. We expect these high mobility IGZO TFTs are stable enough to be used for OLED or other self-luminous displays. We have also demonstrated a prototype 12.3" OLED module for automotive applications. The prototype flexible display showed an excellent brightness uniformity even after bending.