Characterizations of Amorphous IGZO Thin-Film Transistors With Low Subthreshold Swing

摘要

Subthreshold swing (SS) is a key parameter in evaluating the power consumption and material properties of thin-film transistors (TFTs). In this letter, we report an amorphous indium gallium zinc oxide (a-IGZO) TFT with a high-$kappa $$ hbox{SiO}_{2}/hbox{HfO}_{2}$ gate insulator. The device shows a SS of 96 mV/decade and an on-to-off current ratio of $hbox{1.5} times hbox{10}^{10}$. The low SS was attributed to the fully depleted channel state, low interface defects, and efficient modulation of the device. With low defect states, the device demonstrates only 2.71% change of operating currents after $hbox{1.5} times hbox{10}^{4} hbox{s}$ stress.