Low temperature of 150 ℃ processed igto thin-film transistors for flexible display application

Abstract

The high-performance amorphous In-Ga-Sn-O (a-IGTO) thin-film transistors (TFTs) was fabricated with plasma-enhanced atomic layer deposition (PEALD)-derived Al2O3 high-k gate dielectric at a maximum processing temperature of 150 ℃. During the deposition of Al2O3 dielectric on a-IGTO films, the hydrogen (H) and excess oxygen (Oi) defects from the Al2O3 act significant role on TFTs operation. The amounts of H and Oi can be controlled by adjusting oxygen plasma density in radio-frequency (rf) of PEALD. The optimized a-IGTO TFT exhibit high-performance electrical properties with field-effect mobility (µFE) of 58.8 cm2/Vs, subthreshold gate swing (SS) of 0.12 V/decade, threshold voltage (VTH) of 0.5 V.