Effect of Self-Assembled Monolayer (SAM) on the Oxide Semiconductor Thin Film Transistor

In this paper, we proposed the self-assembled monolayer (SAM) as a protection layer against plasma and chemically induced damages to the back interface of an oxide semiconductor during the deposition of the passivation layer. When a thin-film transistor (TFT) is passivated with plasma-enhanced chemical-vapor deposition (PECVD) SiO_x and solution-based materials, the back interface of the oxide semiconductor could be exposed to plasma and chemically induced damages, respectively. We employed SAMs on the back surface of the oxide semiconductor prior to the passivation process to suppress such damage. The hydrophobic Cl-SAM (3-chloropropyltriethoxysilane) suppressed the degradation in mobility and subthreshold slope (SS) due to ion bombardment during plasma treatment. The hydrophobic CH₃-SAM (octyltriethoxysilane) successfully blocked chemically induced damage due to solution-based passivation.