Record Transconductance in Leff~30 nm Self-Aligned Replacement Gate ETSOI nFETs Using Low EOT Negative Capacitance HfO2-ZrO2 Superlattice Gate Stack

We demonstrate short channel, extremely thin SOI (ETSOI, $6\lt \mathrm{nm}$), replacement gate nFETs down to effective gate length $(L_{\text{eff}})\sim 30\mathrm{~nm}$ with low equivalent oxide thickness (EOT) negative capacitance (NC) $\mathrm{HfO}_{2}-\mathrm{ZrO}_{2}$ superlattice (HZH) gate stack [1–2]. Inversion capacitance measurement shows an EOT of ~ 7 Å, which is ~ 2.5-Å lower than typical industry HfO
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dielectrics. The transistors show record intrinsic transconductance $(g_{\mathrm{mi}})-2.11\mathrm{mS}/\mu\mathrm{m}$, rivaling what is achieved in much shorter channel length $(18\mathrm{~nm})$ commercial devices such as 22FDX
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technology. Importantly, the $g_{\mathrm{m}}-L_{\mathrm{g}}$ scaling trends deviate from industry benchmarks, showing that much larger $g_{\mathrm{mi}}$ is achievable at the same channel length. Despite significantly worse series resistance, the devices show favorable performance in $I_{\text{on}}vsI_{\text{on}}/I_{\text{off}}$ tradeoff, providing larger $I_{\text{on}}$ and lower $I_{\text{off}}$ compared to industrial benchmarks of similar channel length.