Transient analysis of the CMOS-like a-Si:H TFT inverter circuit

The dynamic characteristics of a CMOS-like a-Si:H thin-film transistor (TFT) inverter circuit which utilizes the ambipolar property of the TFT are analyzed and modeled. The time-dependent characteristics of a-Si:H TFTs which originate from charge trapping and detrapping are characterized and modeled by shifts in the flat-band voltage. Based on a previously developed static model for the drain current, dynamic operation of the CMOS-like inverter into a load capacitance is described. To speed up the switching process, several device parameter optimizations are presented. Transient characteristics of the inverter are accurately analyzed and predicted by combining the time-dependent response of TFTs with the dynamic operation of the inverter. It is shown that some types of charge trapping can be beneficial for the CMOS-like inverter dynamic speed.<
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