Drain-Induced-Barrier-Lowing-Like Effect Induced by Oxygen-Vacancy in Scaling-Down via-Contact Type Amorphous InGaZnO Thin-Film Transistors

This investigation considers a method to ameliorate drain induced barrier lowing behavior in amorphous-indium-gallium-zinc-oxide thin-film transistors. The V
_th
is found to shift negatively when increasing the I
_D
-V
_G
measurement condition V
_D
from 0.1 to 15 V. The current-voltage curves show that this degradation is caused by the effective channel length (L
_eff
) being shorter than the mask channel length (L). Using the transmission line method to extract L
_eff
, we discover that the degradation will be completely suppressed by an annealing treatment. As a result, the degradation mechanism of shorter channel length a-IGZO thin film transistors is due to oxygen-vacancies which are located between the channel and the source/drain junction.