High-stability transparent amorphous oxide TFT with a silicon-doped back-channel layer

Abstract

We significantly reduced various electrical instabilities of amorphous indium gallium zinc oxide thin-film transistors (TFTs) by using the co-deposition of silicon on an a-IGZO back channel. This process showed improved stability of the threshold voltage (V (th) ) under high temperature and humidity and negative gate-bias illumination stress (NBIS) without any reduction of IDS. The enhanced stability was achieved with silicon, which has higher metal-oxide bonding strengths than gallium does. Additionally, SiO (X) distributed on the a-IGZO surface reduced the adsorption and the desorption of H2O and O-2. This process is applicable to the TFT manufacturing process with a variable sputtering target.