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 cm²/Vldrs with on-to-off current ratios up to 10⁶. Excellent short channel characteristics were also obtained with a small shift of the threshold voltages and no degradation of subthreshold slopes as V_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.