Screen-Printed Cu Source/Drain Electrodes for a-InGaZnO Thin-Film Transistors

We report screen-printed copper source/drain electrodes for a-InGaZnO (a-IGZO) thin-film transistors (TFTs). The best electrical characteristics of the a-IGZO TFTs were a field-effect mobility of 2.06 cm2/Vs, a threshold voltage of 3.40 V, an on/off current ratio of 6.0 × 103A/A, and a subthreshold swing of 7.02 V/decade. Resulting TFT performances indicate that blocking the inter-diffusion of Cu and impurities is a key factor to fabricate low leakage current and high performance a-IGZO TFTs with printed Cu S/D electrodes.