Spray pyrolyzed fluorinated inorganic-organic passivation for solution-processed a-InZnO thin-film transistors

Abstract

Reliability is largely considered an important device requirement for commercial electronic devices. In this work, the reliability of solution-processed amorphous indium zinc oxide (a-IZO) thin-film transistors (TFTs) were evaluated through incorporation of inorganic-organic fluorinated polysilsesquioxane (PSQ:F) passivation deposited through spray pyrolysis (SP) and spin coating (SC) techniques. The barrier property of SP and SC PSQ:F passivation layers were examined under positive and negative bias stress tests and both devices revealed superior stability with smaller threshold voltage shift of 0.9 V/−0.4 V and 1.0 V/−0.2 V respectively, after 10000 s. In addition, both PSQ:F films were confirmed to have an excellent hydrophobic property compared to a-IZO film hindering moisture adsorption. Futheremore, XRR data demonstrates that through SP deposition technique, higher density PSQ:F passivation layer was achieved which inhibits the interaction between the ambient atmosphere and the exposed back-channel region efficiently. Enhancement in the reliability and electrical performance of a-IZO TFTs were achieved through combination of additional fluorine additives from PSQ:F with spray pyrolysis deposition technique.