ScholarWorks@성균관대학교

초록

As amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) become essential for next-generation displays, controlling oxygen vacancies (VO) is critical for ensuring performance and stability. In this work, the impact of the N2/O2 gas flow ratio during post-deposition annealing (PDA) on the chemical and electrical properties of a-IGZO TFTs was investigated. X-ray photoelectron spectroscopy (XPS) analysis revealed that the optimal 3:1 (N2/O2) mixed ambient achieved a superior balance between carrier generation and defect passivation, whereas N2-only and O2-only conditions resulted in excessive defects or carrier suppression, respectively. Consequently, the device annealed under the 3:1 condition exhibited excellent switching characteristics, including a saturation mobility (µsat) of 8.4 cm2 V−1 s−1, a steep subthreshold swing (SS) of 0.54 V/dec, and a high on/off ratio of 1.99 × 106. Furthermore, reliability evaluations under positive bias stress (PBS) demonstrated significant improvement, with the threshold voltage shift (△Vth) decreasing from 3.5 V (N2-only) to 0.4 V (3:1 mixed). These findings suggest that the 3:1 mixed gas annealing process serves as a promising approach for realizing high-performance and reliable a-IGZO TFTs.

키워드