Abnormal Increment Substrate Current After Hot Carrier Stress in n-FinFET

This letter investigates the mechanism of abnormal substrate current (
$\text {I}_{\text {sub}}$
) after hot carrier stress (HCS) in fin field effect transistors (FinFETs). Traditionally, after HCS, the drain current and
$\text {I}_{\text {sub}}$
of the saturation region will continue to decrease. In this work, however,
$\text {I}_{\text {sub}}$
first decreased and then exhibited a gradual abnormal rise. This abnormal
$\text {I}_{\text {sub}}$
behavior was investigated by different measurement methods and was determined to be due to trap-assisted tunneling. This study first uses different operating voltages to prove the proposed model, then applies a variable temperature stress condition to confirm the model. Finally, a junction current measurement is used to determine the location of defect generation.