Characteristics of the Series Resistance Extracted From Si Nanowire FETs Using the Y-Function Technique

Abstract

The series resistance, R(sd) in silicon nanowire FETs (Si-NWFET) is extracted unambiguously, using the Y-function technique, in conjunction with the drain current and transconductance data. The volume channel inversion in Si-NWFET renders the charge carriers relatively free of the surface scattering and concomitant degradation of mobility. As a result, the Y-function of Si-NWFET is shown to exhibit a linear behavior in strong inversion, thereby enabling accurate extraction of R(sd). The technique is applied to nanowire devices with channel lengths 82, 86, 96, 106, 132, and 164 nm, respectively. The extracted R(sd) values are shown nearly flat with respect to the gate voltage, as expected from Ohmic contacts but showed a large variation for all channel lengths examined. This indicates the process parameters involved in the formation of series contacts vary considerably from device to device. The present method only requires a single device for extraction of R(sd) and the iteration procedure for data fitting is fast and stable.