NBTI: An Atomic-Scale Defect Perspective

We utilize a combination of MOSFET-gate controlled diode DC-IV measurements and a very sensitive electrically-detected electron spin resonance technique called spin-dependent recombination to observe and identify defect centers generated during NBTI in fully processed SiO₂ and plasma nitrided oxide (PNO)-based pMOSFETs. In SiO ₂ devices, we observe the NBTI-induced generation of two Si/SiO₂ interface silicon dangling bond centers (P_b0 and P_b1) and very likely an oxide silicon dangling bond center (E´). Our observations indicate that both P_b0 and P_b1 defects play major roles in these SiO₂-based devices and also suggest that E´ centers could play an important role. In PNO devices, we observed the NBTI-induced generation of a new defect center which is fundamentally different from the P_b0/P_b1 defects generated during NBTI in SiO₂ devices. Our results indicate that it plays a dominating role in NBTI-induced interface state generation in thin PNO devices and also exhibits a post-negative bias temperature stress (NBTS) recovery. Although we observe different interface state defects, we observed essentially equivalent activation energies in both the SiO₂ and PNO devices