Temperature Dependence of Substrate and Drain–Currents in Bulk FinFETs

The temperature $(T)$ dependence of $I_{\rm SUB}$ and $I_{D}$ in bulk FinFETs was investigated for the first time. Both n- and p-channel devices with thin fin body width showed the abnormal increase of $I_{\rm SUB}$ at high $T$, which can be explained by stress-induced bandgap narrowing. $I_{\rm SUB}$ and $I_{D}$ were investigated as parameters of $T$ and fin body width $(W_{\rm fin})$. It was shown that thinner $W_{\rm fin}$ gets higher stress. With increasing $T$, the $I_{D}$ of n-channel bulk FinFET with thinner $W_{\rm fin}$ is increased since electron mobility is increased by tensile stress. The threshold voltage decrease becomes significant with decreasing $W_{\rm fin}$ by the bandgap narrowing, which contributes to the $I_{D}$ increase. The $I_{\rm SUB}/I_{D}$ of n-channel bulk FinFET was studied by changing $W_{\rm fin}$ and $ \hbox{1}/V_{\rm DS}$ as a parameter of $T$.