Self-Heating Aware Threshold Voltage Modulation Conforming to Process and Ambient Temperature Variation for Reliable Nanosheet FET.

Internal and external process variations severely affect the device threshold voltage (Vth) and, in turn, the device's reliability. For the first time, this paper presented a thorough analysis of the self-heating aware Vth variation of a Nanosheet FET and, thus, the device's aging. Using well-calibrated TCAD models, we evaluated the 'change in Vth' and performed an extensive design space exploration to analyze: (i) the impact of work function (WF) modulation owing to metal grain sizes and effective grains (for confined dimensions) on Vth variation; (ii) the impact of ambient temperature (TA) on Vth variation; (iii) the influence of trap charges on device characteristics; (iv) how the consideration of RDF impacted Vth; (v) the device's aging, i.e., end of a lifetime (EOL). These investigations provided guidelines for designing a reliable Nanosheet FET (NSFET) to investigate and mitigate early aging.