Study of low frequency noise in vertical NW-Tunnel FETs with different source compositions

This work studies the low frequency noise (LFN) behaviour of vertical nanowire Tunnel-FETs (NW-TFETs) with Si or Ge sources, where the latter devices have different HfO₂ thicknesses (2nm and 3nm) in the gate stack. The presence of Ge in the source yields an increase in the current noise power spectral density (Sid) at low frequency, while Sid is reduced for the thinner HfO₂, due to the reduction of the oxide trap density. The experimental noise behaviour can be explained by the standard Sid model for MOSFETs, when replacing the effective gate length (L_eff) by the tunneling length (L_T).