Transient and Steady State Carrier Transport under High Field Stresses in SONOS EEPROM Device

Abstract

The carrier transport model of tunneling oxide in a polysilicon-oxide-nitride-oxide-silicon (SONOS) device has been developed. The model is deduced from WKB approximation, and uses Fermi-Dirac statistics. Using the J-E and accompanied by Arnett's trapping model, the switching behavior of the SONOS device can be predicted in a very wide range of switching times from 1 µs to 0.1 s. The steady-state charge distribution and electric field in Si3N4 are also calculated. From Arnett's fundamental equations of Si3N4, we deduce the steady-state equations which describe the electric field and trapping charges. The trapping parameters and detrapping factor ν are discussed and the results are obtained via computer for different temperatures and stress voltages, which are based on the current measurement of SONOS devices. We find that the detrapping effect is somewhat less dominant compared to the trapping effect in our simulations.