Hysteresis of transistor characteristics of amorphous IGZO TFTs studied by controlling measurement speed

Abstract

We investigate the hysteresis in the transfer characteristic of amorphous indium-gallium-zinc-oxide thin-film transistor by controlling the sweep waveform of the gate voltage (Vg) provided by parameter measure unit. It is conventionally studied by double sweeping Vg with the default setup of the source measure units, which speed may vary with the current level. By manipulating the step time of sweeping Vg, we found that the response time of charge traps or donor-like states is in the range that overlaps with the conventional time step in the measurement and must be considered.