A Facile Doping Process of the Organic Inter-Layer Dielectric for Self-Aligned Coplanar In-Ga-Zn-O Thin-Film Transistors

A new doping technique to form the conductive source/drain regions of self-aligned coplanar In-Ga-Zn-O (IGZO) thin-film transistors (TFTs) was demonstrated. The electrical resistivity of the IGZO film was reduced to $3.8{\times } {10}^{-{4}} \Omega \cdot $ cm after simply coating the organic inter-layer dielectric thin film. The carrier mobility at the saturation region and subthreshold swing of the fabricated IGZO TFTs were 18.4 cm ² /Vs and of 150 mV/dec, respectively. The channel width-normalized contact resistance was estimated to be as low as $12~\Omega \cdot $ cm, verifying the ohmic behaviors. Robust device stabilities were also confirmed under bias-stress and temperature-stress conditions.