Influence of the metallic electrodes on the contact resistance of the ink-jet printed In-Ga-Zn oxide TFTs

摘要

The influence of the metallic electrode materials on the contact resistance of the ink-jet printed In-Ga-Zn oxide (IGZO) thin film transistors (TFTs) is investigated in this paper. Various electrodes, including Al, Ti/Au, ITO and Au were examined based on the inverted staggered (bottom gate top contact) IGZO TFTs. Without additional annealing, the contact resistance increased with the increase of the work function of the electrode, which is Al ＜ Ti/Au ＜ ITO ＜ Au. However, the contact resistance behavior changed drastically for different electrodes under different annealing temperature from 200 to 500 ℃. The different behavior of the electrodes upon annealing was regarded to the contact modes changed between ohmic and Schottky contact. The finding provides a clue for electrode selection for the ink-jet printed IGZO TFTs to minimize the contact resistance and optimize the device performance according to the process conditions.