Optimizing the Properties of InGaZnO(x) Thin Film Transistors by Adjusting the Adsorbed Degree of Cs(+) Ions

To improve the performance of amorphous InGaZnO(x) (a-IGZO) thin film transistors (TFTs), in this thesis, Cs(+) ions adsorbed IGZO (Cs-IGZO) films were prepared through a solution immersion method at low temperature. Under the modification of surface structure and oxygen vacancies concentrations of a-IGZO film, with the effective introduction of Cs(+) ions into the surface of a-IGZO films, the transfer properties and stability of a-IGZO TFTs are greatly improved. Different parameters of Cs(+) ion concentrations were investigated in our work. When the Cs(+) ions concentration reached 2% mol/L, the optimized performance Cs-IGZO TFT was obtained, showing the carrier mobility of 18.7 cm(2) V(−1) s(−1), the OFF current of 0.8 × 10(−10) A, and the threshold voltage of 0.2 V, accompanied by the threshold voltage shifts of 1.3 V under positive bias stress for 5000 s.