AC hot carrier lifetimes in oxide and ROXNOX N-channel MOSFET's

Abstract

A recently developed model for AC hot carrier degradation is extended to low-temperature operation as well as to ROXNOX (reoxidized nitrided oxide) dielectrics. Three hot carrier damage mechanisms are incorporated into the model: interface states and oxide electron traps created at low gate voltages, interface states created at medium gate voltages, and oxide electron traps created at high gate voltages. It is shown that the quasi-static contributions of these three mechanisms fully account for hot-carrier degradation under AC stress. The model is shown to be valid at 173 K and 295 K for both typical and worst-case AC stress waveforms found in CMOS circuits. It is also shown to be valid for ROXNOX MOSFETs.<>