Reliability Assisted Electro-Physical Modelling of Radiation-Induced Resistance Fluctuation in Nanosheet FET

The incidence of alpha (α) particles on a device induces single-event transients (SET), leading to serious reliability concerns related to device degradation and failure. Exposure to high-energy α-radiation can therefore alter device performance, particularly in highly confined device architectures (e.g., Nanosheet FETs), where the channels are extremely sensitive to charge deposition. In this work, we present a comprehensive investigation of α-particle-induced reliability assessment of Nanosheet FET (NSFET) using well-calibrated TCAD models. Upon striking, high-energy α particles generate electron-hole pairs (EHPs), which alter the device's resistivity/conductivity. The magnitude of the induced transients increases with linear energy transfer (LET), while the conductivity degradation is mainly attributed to the hole population generated during EHP formation. In our TCAD experiment, we varied the strike energy from 1 to 5 MeV, the strike time from 10 ps to 2.5 μs, and the strike angle from 0° to 60°. Further, the strike locations were varied to assess resistivity modulation in all possible scenarios. In the worst-case scenario, the maximum current of 1.86 μA is observed at a strike interval of 10 ps in the drain extension. Moreover, we develop a resistivity model to capture the α-radiation-induced resistivity modulation using the transmission line method (TLM). The model predictions closely match the simulation data, confirming the model's validity. Thus, the proposed design guidelines and model provide an efficient means of assessing the effects of alpha radiation on the resilience of NSFETs.