Impact of Off-State Stress and Negative Bias Temperature Instability on Degradation of Nanoscale pMOSFET

This letter investigates the impact of dynamic stress on the degradation of a nanoscale p-channel metal-oxide-semiconductor field-effect transistor (pMOSFET). Experimental results indicate that the OFF-state stress generated donorlike interface traps N-it and electron oxide traps, localized near the drain. The ON-state stress produced the negative bias temperature instability which generated N-it's and positive oxide charges Q(ox) distributed uniformly in the channel. Although the electrons trapped by the OFF-state stress decreased the threshold voltage vertical bar V-th vertical bar, they were detrapped readily by the subsequent ON-state stress. A dynamic stress caused the nanoscale pMOSFET to build up N-it and positive Q(ox), which increased the vertical bar V-th vertical bar significantly. These new observations indicate that the combined dynamic process can significantly influence the reliability of scaled CMOS inverter circuits.