Characterization of Failure Mechanisms and Failure Rate of Oxide Wearout by Hot Electron Using D.C. and A.C. Substrate Electron Injection

Abstract

ABSTRACTDetermination of the failure mechanisms and failure rate of oxide wearout by hot carrier injection in submicron metal-oxide-semiconductor field-effect-transistor (MOSFET) requires special test structures to isolate the oxide field dependence of oxide trap generation and charging. A bipolar-MOS transistor (BiMOS) structure is used which d.c. injects substrate electrons into the gate oxide of a MOS transistor by forward biasing the emitter-base n+/p junction of a vertical n+/p/n-inversion-layer bipolar junction transistor. The field and temperature dependences enable a separation of thermal and tunnel electron detrapping rates at low and high oxide field from the generation rate of new oxide traps at high fields. Pulsed a.c. substrate electron injection in a n+ sourced metal-oxide-semiconductor capacitor (SMOSC) structure is used to characterize the field dependence of oxide degradation in chlorinated oxides.