Design and Analysis of a Dual-Metal-Implanted Triple-Material Cylindrical Gate-All-Around Nanowire FET with Negative Differential Resistance and Negative Transconductance Behaviors

Abstract

In this paper, we introduce three new structures of a cylindrical gate-all-around nanowire (NW) field-effect transistor (FET) to achieve negative differential resistance (NDR) and negative transconductance (NTC) behaviors. In the first structure, only one metal is implanted in the channel near the drain of the dual-material cylindrical gate-all-around NWFET based on the energy band profile modulation to obtain the NDR behavior. To achieve NTC behavior, another metal is implanted in the channel near the source; therefore, the second structure has both the NDR and NTC behaviors. In the final structure, the use of a triple-metal gate is proposed to improve the peak-to-valley current ratio. The NTC behavior occurs when the increase in VGS creates a positive lateral electric field in the channel, which causes the potential barrier tunneling (PBT) to decrease. The cause of the positive electric field formation is the cavity in the channel’s potential barrier due to implanted metals. Furthermore, by increasing VDS, the high electron scattering caused by the high electric field at the beginning of the drain region is increased and causes the electron drift velocity and IDS to decrease. Consequently, the NDR behavior is achieved. The structures are carefully simulated using numerical simulation based on non-local tunneling, and also the transfer characteristics (IDS − VGS) and the output characteristics (IDS − VDS) are attentively analyzed and examined.