A New Observation of the Elliot Curve Waveform in Charge Pumping of Poly-Si TFTs

In the charge pumping (CP) measurement of poly-Si thin-film transistors (TFTs), the Elliot curve is found to be irrelevant to the flat-band voltage (V_fb) and threshold voltage (V_th) and hence does not follow the traditional MOSFET CP rule. Instead, a new correspondence between the TFT Elliot curve and device key parameters is observed. The critical onset voltages of the CP current are the threshold gate voltages for channel inversion and accumulation, which can be experimentally extracted by capacitance-voltage measurement. They are consistent with the general CP model and reduce to V_fb and V_th in MOSFETs.