The understanding of the trap induced variation in bulk tri-gate devices by a novel random trap profiling (RTP) technique

Not only the popular random dopant fluctuation (RDF), but also the traps, caused by the HC stress or NBTI-stress, induce the Vth variations. To identify these traps, for the first time, a unique random trap profiling feasible for 3D device applications has been demonstrated on trigate devices. For such devices, the oxide traps are generated not only near the drain side but also on the sidewall, after hot carrier (HC) and NBTI stresses. More importantly, the Vth variation in pMOSFET under NBTI becomes much worse as a result of an additional surface roughness effect. This method provides us a valuable tool for the diagnosis of reliability in 3D devices (e.g., FinFET).