A coupled I(V) and charge-pumping analysis of Stress Induced Leakage Currents in 5nm-thick gate oxides

Abstract

Stress Induced Leakage Currents (SILC) are studied in 5 nm-thick oxides on both capacitors and N-MOSFET's after homogeneous FOWLER-NORDHEIM injections under high field stress (<9MV/cm) for both polarities and localized Hot-Carrier injections. Standard I(V) and high-frequency C(V) curves are used to monitor the degradation in correlation to the Charge-Pumping (CP) technique. A systematic increase is found in SILC at low field (4–8 MV/cm) up to two orders of magnitude after FN injections and we report on the observation of SILC after localized hot hole injection. We find a correlation between the SILC increase and the interface state (N it) generation. No trapped charge is detected in 5 nm-thick gate oxides during FN stresses but the presence of slow states is evidenced, supporting a tunneling process through neutral oxide traps as a model for SILC.