Robust design of electric-field-assisted nonlocal Si-MOS spin-devices

Abstract

Si-channel spin-transistors, such as a spin-MOSFET (Fig. 1) [1], have attracted considerable attention as a key device for low-standby-power integrated circuits. To realize spin-MOSFETs, understanding of spin dynamics in the Si channel is indispensable. In particular, a technique of quantitatively analyzing spin lifetime in Si MOS inversion channels needs to be developed. The Hanle effect is known to be a powerful tool for evaluating spin lifetime. Recently, we have developed a new analysis technique of spin dynamics in Si channels based on a four-terminal nonlocal (4TNL) technique, referred to as the electric-field-assisted (EFA) 4TNL method (Fig. 2). This technique enables us to evaluate accurate spin lifetime using an application of a specific electric field (E acc ) the channel [2, 3]. Although the electric field enhances the intensity of Hanle-effect oscillation signals, the width (d) of the electrodes strongly affects the waveform of the signals (Fig. 3). In this study, we developed a robust design scheme of EFA-4TNL MOS devices that can accurately determine spin lifetime as long as an appropriate E acc is applied to the channel.