Carrier separation measurement of leakage current under prebreakdown in ultrathin SiO2 films

The anomalously large gate leakage current observed prior to dielectric breakdown in electrically stressed n+ gate p metal - oxide - semiconductor field-effect transistors is investigated. Carrier separation measurements reveal that the leakage currents are electron tunneling current, and in some cases are accompanied by noticeable hole-related current at low gate voltages. Experimental results demonstrate the close correlation between this phenomenon and soft breakdown in terms of current - voltage characteristics. [copyright] 2001 American Institute of Physics