MOSFET Degradation due to stressing of thin oxide

Oxide and interface traps in 100Å oxide created by Fowler-Nordheim tunneling current have been investigated using capacitor C-V, I-V and transistor I-V measurements. The net oxide trapped charge is initially positive due to hole trapping near the anode interface and, at high fluence, becomes negative due to the trapping of electrons at 60Å from the injector (cathode) interface. Acceptor and donor type interface traps (surface states) peaking at 0.65eV above valence band edge were created by tunneling current from and to the substrate respectively. The interface traps cause degradations in subthreshold current slope and surface mobility. The threshold voltage shift can be either positive or negative under the combined influence of the oxide charge and the interface traps.