Deconvolution of Hot Carrier and Cold Carrier Injection in ZnO TFTs

Positive bias instability stress (PBI) and hot carrier injection stress (HCI) was done on ZnO thin-film transistors (TFTs) with 100°C Al
2
O
3
. The threshold voltage (V
T
), transconductance (g
m
), and subthreshold slope (SS) were monitored. HCI stress with two intermittent sense measurements where the first I
DS
-V
GS
is measured at the drain contact and the second is measured at the source contact to separate the contribution of the hot carrier and cold carrier injection on the V
T
shift. PBI stress was done to determine the viability of the carrier injection separation using only HCI.