Hybrid-Phase Microstructural ITO-Stabilized ZnO TFTs With Self-Aligned Coplanar Architecture

In this letter, hybrid-phase microstructural ITO-stabilized ZnO thin films, which were capped by silane-sourced or tetraethyl-orthosilicate-sourced plasma-enhanced chemical vapor deposition (PECVD) SiO₂ layers, were found to present remarkably different resistivity variation after O₂ annealing treatment. Besides hydrogen-related factors, the silicon-doping phenomenon along with the silane-sourced PECVD process was also responsible for the durable low-resistivity state of the hybrid-phase microstructural ITO-stabilized ZnO thin films. Via a combination of differentiated PECVD and O₂ annealing processes, the self-aligned coplanar TFTs were fabricated, and they exhibited good electrical characteristics with an average field-effect mobility of 19.56 cm²/Vs, and a subthreshold swing of 105 mV/decade, as well as robust stability against gate-bias stress.