Analysis of channel electrons scattered in each region of silicon nanodiode at low drain voltage using nonequilibrium Green’s function approach

Abstract

We analyzed channel electrons caused by scattering on the drain current of a silicon nanodiode. Electrons in the channel region are classified by the scattering positions: the source, channel, and drain regions. We focused our attention on the operation in a low-voltage range to study ultralow-power operation. To analyze electron transport in the device, we employed the nonequilibrium Green’s function (NEGF) approach, which takes a complete quantum effect into consideration. It was found that channel electrons backscattered from the drain region cause a negative drain current when the drain voltage decreases. However, scattered channel electrons contribute only slightly to the drain current owing to the presence of substantial ballistic channel electrons, although the average velocity of scattered channel electrons is as large as that of ballistic channel electrons in a low-drain-voltage range. This result is beneficial for the development of future ultralow-power devices.