Charge pumping in thin film transistors

Optimization of charge pumping technique in polysilicon TFTs for geometric effect elimination and trap state density extraction

“…The maximum I cp is seen to gradually increase with V ph , which is in agreement with a previous CP model [2]. Compared to previous CP studies in polysilicon TFTs [3,7], the optimized I cp shown here is clearly more suitable for the D t extraction. (6).…”

“…Charge pumping (CP) technique has been used as a powerful and reliable method for interface state density extraction in MOSFETs [2]. So far, a few works have been reported to characterize the trap properties of polysilicon TFTs by using CP [3][4][5][6][7][8][9][10]. It has also been employed to investigate the degradation of polysilicon TFTs [11,12].…”

“…It has also been employed to investigate the degradation of polysilicon TFTs [11,12]. However, unlike in MOSFETs, CP never becomes a standard characterization technique for polysilicon TFTs, because it is still not sufficiently reliable and some ill-understood phenomena are not clarified [3,5,7,12], among which the geometric effect is an important one.…”

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

“…Moreover, Elliot curves are also used to investigate the device degradation [2]. However, their waveforms in poly-Si thin-film transistors (TFTs) were far from ideal, which previously was ascribed to the fabrication process [4] or some unknown traps [5]. It prevents the clarification of the correspondence between the device characteristics and the Elliot curve.…”

“…It prevents the clarification of the correspondence between the device characteristics and the Elliot curve. Thus, the traditional MOSFET CP rule was still followed in poly-Si TFTs [4]- [8].…”