Theory of the Junctionless Nanowire FET

In this work we model the electrical properties of the junctionless nanowire field-effect transistor, which has recently been proposed as a possible alternative to the junction-based FET. The analytical model worked out here assumes a cylindrical geometry and is meant to provide a physical understanding of the device behavior. Most notably, it aims to clarify the motivation for its nearly-ideal subthreshold slope and its excellent on-state current, while being a depletion device with a lower electron mobility due to impurity scattering. At the same time, the model clarifies a constraint binding the allowable value of the doping density per unit length and its impact on the overall device performance. The device variability and the parasitic S/D resistances are identified as the most important limitations of the junctionless NW-FET.