Comparison between recoverable and permanent NBTI variability components

In this paper, we present a statistical analysis of recoverable and permanent NBTI components. Measurements are performed on PFET devices issued from ST Microelectronics 28nm FDSOI technology, covering a wide range of device dimensions W and L. We analyzed NBTI degradation and recovery measured at μs time scale, resulting from AC and DC stress. We were able to confront VTh drift variability during stress and relaxation phase and evidence significant differences of variability between stress and relaxation phase.