Propagation Delay Evaluation for Spatial Wavefunction Switched (SWS) FET-Based Inverter

Abstract

This paper evaluates the propagation delay of a four-state/two-bit spatial wavefunction-switched field-effect transistors (SWS) FET-based inverter. The SWS-FET has two or more vertically stacked quantum-well or quantum dot (QD) layers where the magnitude of the gate voltage determines the location of carriers in the upper or lower channel. A calibration method based on an analytical propagation delay model expanded for the SWS-FET based inverter to account for the multiple quantum wells within the device. Cadence iterative simulations are used for calibrating the SWS inverter size to reach a symmetrical propagation delay for the four logic transitions. The SWS transfer characteristic and the inverter circuit time specifications are obtained by integrating the BSIM (Berkeley Short-channel IGFET Model) and the Analog Behavioral Model (ABM). Calibration and adjustment of the contributing parameters of the model leads to the improvement of the device accuracy for circuit designs based on SWS-FET technology.