Surface-Roughness-Induced Variability in Nanowire InAs Tunnel FETs


We present a comparative study of the surface-roughness (SR)-induced variability at low supply voltage $V_{DD} = hbox{0.3} hbox{V}$ in nanowire InAs tunnel FETs and strained-silicon (sSi) MOSFETs. By exploiting a 3-D full-quantum approach based on the Non-Equilibrium Green's Function formalism, we show that the $I_{rm on}$ variability in InAs tunnel FETs is much smaller than the $I_{rm off}$ variability, whereas for $V_{DD} = hbox{0.3} hbox{V}$, the sSi MOSFETs working in the subthreshold regime present similar $I_{rm on}$ and $I_{rm off}$ variability. We explain the smaller $I_{rm on}$ compared with $I_{rm off}$ variability of InAs tunnel FETs by noting that in the source depletion region, where tunneling mainly occurs for $V_{GS} = V_{DD}$, microscopic subband fluctuations induced by SR are small compared to macroscopic band bending due to the built-in potential of the source junction and to the gate bias. This results in SR-induced variability that is larger in InAs tunnel FETs than in sSi MOSFETs.

Did you like this research project?

To get this research project Guidelines, Training and Code... Click Here

Ready to Complete Your Academic MTech Project Work In Affordable Price ?

Project Enquiry