Analysis of Self-Heating Effect on Short Channel Amorphous InGaZnO Thin-Film Transistors

We report on a thin-flim transistor (TFT) degradation encountered in short channel amorphous indium-gallium-zinc-oxide TFTs under high applied power condition leading to self-heating. Negative shift was observed in the initial stage of stress period followed by positive shift with severe degradation. To understand the causes of this phenomenon in depth, trap density-of-states were measured by photo-excited charge-collection spectroscopy and time-dependent recovery of stressed device samples was also studied. As a result, we found that the combination of hot carrier effect and self-heating in channel was responsible for the degradation.