Sub-THz frequency analysis in nano-scale devices at room temperature

Abstract

In this work, we have performed a Monte Carlo (MC) simulation to study the THz response of two types of nanometer devices at room temperature, so called three terminal Y-Branch Junction (YBJ) [1] and Ballistic Deflection Transistor (BDT) [2]. This sub-millimeter frequency range in the electromagnetic spectrum is attracting more and more interest due to its broad range of applications, from medical diagnostic to industrial quality control or security-screening tools. Our modeling tool consists of an ensemble MC simulator of the electron dynamics, self-consistently coupled with a 2D Poisson solver (with the finite differences approach) [3]. This tool is quite appropriate for time domain simulation of these ballistic devices at room temperature, as it has already been demonstrated in previous works that provides very good match to measured results [3]. Both types of semiconductor nanodevices, based on high mobility InGaAs channels, due to their small size have a very high surface/volume ratio, so that surface effects at the boundaries play a significant role in the device behavior. To include the depletion effect, a negative surface charge density, σ, is included in the simulator, with a value extracted from measurements.