Reliability Improvement Top-Gate Self-Aligned IGZO TFTs with Cu Electrode For AMOLED Display

The oxide semiconductor, a-IGZO, has been the object of extensive investigation in recent years due to its advantages as the active layer in TFTs. These include high mobility, low process temperature and large-area uniformity. Meanwhile, large-size and high-resolution display will be the trend in the future. For the display to have an integrated TFT drive circuit, the channel length (L) of TFTs should be as short as possible. In this work, a top-gate self-aligned oxide amorphous indium-gallium-zinc-oxi (a-IGZO) thin-film transistor (TFT) was examine for active matrix organic light-emitting diode (AMOLED) display. The device with improved gate insulator layer exhibited robust device performance, such as excellent threshold voltage uniformity, high mobility, and good gate bias stress stabilities. Furthermore, remarkable electrical properties of short channel characteristics were achieved with a small shift of the threshold voltages and no degradation of subthreshold slopes, even when the length of the short channel is less than 4 nm.