# Comparison of Various Factors Affected TID Tolerance in FinFET and Nanowire FET
## 2 Simulation Methodology
### TID Simulation of Various Factors  
The TID simulation used the Silvaco victory device software [18]. The Klaassen model used in the simulation reflects various parameters such as electron and hole mobility, trap parameters, and recombination parameters [19; 20; 21; 22; 23]. The trap-detrap model parameters in the oxide region by radiation were used in the same way as in [24]. For a more precise simulation, the interfacial trap coefficient between SiO\({}_{2}\) and HfO\({}_{2}\) was calculated by introducing an interfacial trap parameter between the insulators. We generated the corresponding I\({}_{\text{D}}\)-V\({}_{\text{G}}\) curves by applying the TID effect. The radiation source was a \(\gamma\)-ray irradiation performed using a Co\({}^{60}\) source [25]. Radiation was irradiated 1 rad/s for the devices. The input V\({}_{\text{DD}}\) was equal to 0.65 V and the sweep V\({}_{\text{G}}\) was in the range 0-0.7 V for the electrical characteristics of 100 Krad, 1 Mrad, 10 Mrad, and 100 Mrad. The simulation confirmed the TID effect on the structural aspects of the FinFET and 5 ch-NW. All comparative calculations were performed with the same efficiency as the charge capture [9].  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Condition Factor** & **FinFET** & **5 ch-NW** \\ \hline S/D Doping & \(1\times 10^{21}\) (cm\({}^{-3}\)) & \(1\times 10^{21}\) (cm\({}^{-3}\)) \\ Channel Doping & \(1\times 10^{16}\) (cm\({}^{-3}\)) & \(1\times 10^{16}\) (cm\({}^{-3}\)) \\ EOT & 0.812 (nm) & 0.812 (nm) \\ T\({}_{\text{fin}}\), D\({}_{\text{mw}}\)/I\({}_{\text{g}}\) & 6/12 (nm) & 6/12 (nm) \\ H\({}_{\text{fin}}\), H\({}_{\text{mw}}\) & 42 (nm) & 30 (nm) \\ Total area (HfO\({}_{2}\) + SiO\({}_{2}\) + Silicon) & 489.5 (nm\({}^{2}\)) & 474.9 (nm\({}^{2}\)) \\ Oxide area (HfO\({}_{2}\) + SiO\({}_{2}\)) & 237.5 (nm\({}^{2}\)) & 333.6 (nm\({}^{2}\)) \\ \hline \hline \multicolumn{3}{c}{**Parameter explanation**} \\ \hline T\({}_{\text{fin}}\): FinFET’s width & D\({}_{\text{mw}}\): 5 ch-NW’s diameter & \\ L\({}_{\text{g}}\): channel length & H\({}_{\text{fin}}\): FinFET’s height & \\ H\({}_{\text{mw}}\): 5 ch-NW’s total height & & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Design specifications of the FinFET and 5 ch-NW.  
Figure 2: Black line is the I\({}_{\text{D}}\)-V\({}_{\text{G}}\) curve of the FinFET and the red symbol is the I\({}_{\text{D}}\)-V\({}_{\text{G}}\) curve of the 5 ch-NW and shows the calibrated FinFET and 5 ch-NW’s I\({}_{\text{D}}\)-V\({}_{\text{G}}\) curve characteristics for similar conditions. Both were extracted by sweeping V\({}_{\text{G}}\) from 0 to 0.7 V when V\({}_{\text{DD}}\) = 0.65 V.  
To observe VDD influence, the VDD was simulated by varying it from 0.65 V to 0.1 V. The VT shift amount was compared based on the VDD in the TID simulation. We applied the VDD conditions mentioned above to FinFET and 5 ch-NW, and the VG sweep was done in the same way from 0 V to 0.7 V.  
The TID characteristics of the two aforementioned devices according to the changed channel doping concentration were confirmed as the channel doping concentration changed. The TID effect change was confirmed by the VT shift. The channel doping concentration was changed from \(1\times 10^{16}\) cm\({}^{-3}\) to \(1\times 10^{18}\) cm\({}^{-3}\). After changing the channel doping of both the devices, the initial simulation without radiation was compared to the simulation with TID of 10 Mrad.