Short Channel Characteristics of Gallium–Indium–Zinc–Oxide Thin Film Transistors for Three-Dimensional Stacking Memory

Amorphous Gallium–Indium–Zinc–Oxide (GIZO) thin film transistors with short channels of 50 nm were successfully fabricated by e-beam lithographic patterning. The GIZO thin film transistors showed a high mobility of 8.2 $\hbox{cm}^{2}/\hbox{V}\cdot \hbox{s}$ with on-to-off current ratios up to $\hbox{10}^{6}$. Excellent short channel characteristics were also obtained with a small shift of the threshold voltages and no degradation of subthreshold slopes as $V_{\rm DS}$ increased, even with short channel lengths of less than 100 nm. These promising results indicate that the GIZO thin film transistors could be a candidate for selection transistors in 3-D cross point stacking memory.