THRESHOLD-VOLTAGE INSTABILITY IN MOSFET's DUE TO CHANNEL HOT-HOLE EMISSION.

Hydrogen introduced and trapped in the gate oxide of MOSFET's by the silicon-nitride capping process can be activated by emitted holes from the MOSFET channel to produce a large threshold-voltage shift. This effect requires avalanche multiplication in the channel for the production of holes when a dc voltage is applied to the gate. For the pulsed-gate case, the magnitude of the threshold-voltage shift depends significantly on the gate-pulse fall time, cycle time, and duty cycle. In both cases the electric field normal to the Si/SiO//2 interface near the drain aids the emission of holes across that interface. A semiquantitative model is proposed which says that holes can recombine at H//2 molecules and release sufficient energy to cause dissociation.

Duke Scholars

Author Richard B. Fair Electrical and Computer Engineering