Characteristics of short-channel amorphous In-Ga-Zn-O thin film transistors and their circuit performance as a load inverter

摘要

The characteristics of amorphous In-Ga-Zn-O (IGZO) thin film transistors (TFTs) and load inverters with a short channel length were studied. The IGZO TFTs showed a mobility value of >5 cm~2/Vs with a V_(th) value of -1.62 V. No degradation of the TFT properties, such as a negative shift of V_(th) or degradation of the subthreshold slope by the short-channel effect, were observed down to a channel length of 2 μm. A load inverter using an IGZO TFT with a gate length of 2 μm and resistor of 1 MΩ was fabricated and characterized, and a voltage gain of 4 was obtained at a VDD value of 10 V. Additionally, the action of a dynamic inverter operating at frequencies of 1 and 10 kHz was characterized. Complete inverter action was obtained at 1 kHz, while an delay time of 0.53 μs was observed at 10 kHz. These promising results indicate that short channel IGZO TFTs are candidate for TFTs in the display industry, including active-matrix organic light-emitting diodes or multi-view three-dimension TV.