Effects of Carrier Concentration, Indium Content, and Crystallinity on the Electrical Properties of Indium-Tin-Zinc-Oxide Thin-Film Transistors

摘要

We report the effects of carrier concentration $(N_{{rm CH}})$, indium (In) content, and crystallinity $(X_{{rm c}})$ on the electrical properties of indium-tin-zinc-oxide (ITZO) thin-film transistors (TFTs). The ITZO TFT with the lowest $N_{{rm CH}}$, In content, and amorphous phase at the optimized oxygen flow rate has high field-effect mobility a $(mu_{{rm FE}})$ of 37.2 ${rm cm}^{2}/{rm V}cdot{rm s}$, high ON/OFF current ratio $(I_{{rm ON}}/I_{rm OFF})$ of ${sim}1times 10^{{rm 7}}$, and low subthreshold swing (S.S) of 0.93. With increasing $N_{{rm CH}}$, In content, and $X_{{rm c}}$, $mu_{{rm FE}}$, $I_{{rm ON}}/I_{{rm OFF}}$, and S.S surprisingly degraded to 14.4 ${rm cm}^{2}/{rm V}cdot{rm s}$, ${sim}4times 10^{{rm 4}}$, and 4.01, respectively. Our high ITZO TFTs with $mu_{{rm FE}}$ of 37.2 ${rm cm}^{2}/{rm V}cdot{rm s}$, obtained thorough control of the $N_{{rm CH}}$, In content, and $X_{{rm c}}$, was suitable for application to next generation ultrahigh resolution displays as well as high frame rate displays.