Observation of negative bias stressing interface trapping centers in metal gate hafnium oxide field effect transistors using spin dependent recombination

The authors combine metal oxide semiconductor (MOS) gated diode measurements and very sensitive electrically detected electron spin resonance measurements to detect and identify negative bias temperature instability (NBTI) generated defect centers in fully processed Hf O2 pMOS field effect transistors. Both short and long term stressing defects are different from those generated by NBTI in SiSi O2 devices. The spectra generated by long term stressing differ from the short term stressing signals and are somewhat similar to those observed in plasma nitrided oxide SiSi O2 devices. The results suggest that NBTI defects are located in the interfacial Si O2 layer of these Hf O2 devices.