150 $^{\circ}$C Amorphous Silicon Thin Film Transistors With Low-Stress Nitride on Transparent Plastic

Abstract

This paper reports on hydrogenated amorphous silicon (a-Si:H) thin-film transistors (TFTs) processed at 150°C using plasma-enhanced chemical vapor deposition on polyethylene naphthalate (PEN) transparent plastic substrates. We examine the impact of RF deposition power on film stress of amorphous silicon nitride (a-SiNx:H), and resulting TFT performance. Transistors with the lowest stress nitride, yield the best performance in terms of device mobility (~1.1 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /V·s), ON/OFF current ratio (~10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> ) , and gate leakage current (<; 0.1 pA). Stable TFTs are demonstrated with a threshold voltage shift of less than 0.8 V following 10 hours of DC bias stress at 10 V.