Novel self-aligned top-gate oxide TFT for AMOLED displays

TLDR: In this paper, a self-aligned top-gate oxide-semiconductor thin-film transistor (TFT) formed by using the aluminum reaction method has been developed, which has advantages such as small-sized TFTs, lower mask count, and small parasitic capacitance.

Abstract: — A novel highly reliable self-aligned top-gate oxide-semiconductor thin-film transistor (TFT) formed by using the aluminum (Al) reaction method has been developed. This TFT structure has advantages such as small-sized TFTs, lower mask count, and small parasitic capacitance. The TFT with a 4-μm channel length exhibited a field-effect mobility of 21.6 cm2/V-sec, a threshold voltage of −1.2 V, and a subthreshold swing of 0.12 V/decade. Highly reliable TFTs were obtained after 300°C annealing without increasing the sheet resistivity of the source/drain region. A 9.9-in.-diagonal qHD AMOLED display was demonstrated with self-aligned top-gate oxide-semiconductor TFTs for a low-cost and ultra-high-definition OLED display. Excellent brightness uniformity could be achieved due to small parasitic capacitance.