Improvement in the bias stability of amorphous indium gallium zinc oxide thin-film transistors using an O2 plasma-treated insulator

The effects of an ${\text{O}}_2$ plasma-treated ${\text{SiN}}_X$ -based insulator on the interfacial property and the device performances of amorphous indium gallium zinc oxide thin-film transistors ($a$ -IGZO TFTs) were investigated. We tried to improve the interfacial characteristics by reducing the trap density between the ${\text{SiN}}_X$ gate insulator and $a$ -IGZO channel by the ${\text{O}}_2$ plasma treatment. The plasma treated-device performances were remarkably improved. The drastic improvements obtained for the ${\text{O}}_2$ plasma-treated $a$ -IGZO TFTs included excellent bias stability as well as a high field effect mobility $\left({\mu }_{\text{FE}}\right)$ of $19.4{\text{cm}}^2/\text{V}\text{s}$ , an on/off current $\left(I_{\text{ON}}/I_{\text{OFF}}\right)$ of ${10}^8$ , and a subthreshold value $\left(S\right)$ of 0.5 V/decade.