The impact of nitrogen engineering in silicon oxynitride gate dielectric on negative-bias temperature instability of p-MOSFETs: A study by ultrafast on-the-fly I-DLIN technique

Abstract

Degradation of p-MOSFET parameters during negative-bias temperature instability (NBTI) stress is studied for different nitridation conditions of the silicon oxynitride (SiON) gate dielectric, using a recently developed ultrafast on-the-fly I-DLIN technique having 1-mu s resolution. It is shown that the degradation magnitude, as well as its time, temperature, and field dependence, is governed by nitrogen (N) density at the Si/SiON interface. The relative contribution of interface trap generation and hole trapping to overall degradation as varying interfacial N density is qualitatively discussed. Plasma oxynitride films having low interfacial N density show interface trap dominated degradation, whereas relative hole trapping contribution increases for thermal oxynitride films having high N density at the Si/SiON interface.