Impact of process and geometrical parameters on the electrical characteristics of vertical nanowire silicon n-TFETs

We report on the process integration of vertical silicon Tunnel FETs (TFETs) and analyze the impact of process and geometrical parameters on the device behavior. The gate–source overlap is shown to be a critical parameter, especially when the overlap is marginal. The temperature dependence also suggests that trap-assisted tunneling injection mechanism is at the origin of the degraded onset characteristic of the vertical TFET, likely due to a large interface trap density and that improvement in the passivation of the surface of the vertical nanowires should be beneficial.

► We report on the process integration of vertical silicon Tunnel FETs. ► We analyze the impact of process and geometrical parameters on the device behavior. ► We show that the gate–source overlap is a critical parameter. ► Temperature dependence indicates that trap-assisted tunneling results in degraded swing. ► Maintaining low material and interface defectivity is important to reach a sub-60 mV/dec swing.