Characterization of breakdown in ultrathin oxides by hot carrier emission

Abstract

The localized transport during progressive oxide breakdown was described using hot carrier luminescence (HCL) excited at low voltage across ultrathin gate oxides. It was observed that the transitions from stress-induced leakage currents to reversible breakdown to final breakdown were accompanied by changes in the efficiency of the emission showing an evolution from inelastic to elastic transport. The HCL images of fresh and voltage stressed nFETs (field effect transistor) show a progressive breakdown at a single spot. It was shown that HCL from electrons tunneling through ultrathin gate oxide at low voltages provides information about the breakdown in these systems.