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TFT on Silicon
Low Temperature TFT Device: a-Si
·The switching is characterized by the subthreshold slope
S (or subthreshold swing, or SS):
1
-
(log I )
S =
D
(mV/dec)


VG

·A large S typically comes from high defect density at the
interface between the gate dielectric and the channel.
·Besides large S, the leakage current (Ioff) also exists when
VG<VT and low-temp. process shows large Ioff.

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