Extended design window of resonant plasma-wave transistor for terahertz emitter by considering degenerate carrier velocity model with Fermi–Dirac distribution

Abstract

In this work, we propose extended design window which is helpful to judge whether the plasma-wave transistor (PWT) operates as a resonant terahertz (THz) electromagnetic (EM) wave emitter. When metal–oxide–semiconductor field-effect transistor (MOSFET) is on strong inversion which is believed to be an operation regime of PWT THz emitter, Boltzmann statistics is no longer valid and degenerate Fermi–Dirac distribution should be considered. Based on degenerate carrier velocity model, we report the increased maximum channel length (Lmax) to 17 nm for strained silicon (s-Si) PWT with assuming μ = 500 cm2·V−1·s−1. As mobility is enhanced, it is possible to observe two emission spectrums [fundamental (N = 1) and third (N = 3) harmonics] in a specific operation range. Theoretically, increment of Lmax for enhanced μ is limited to near 35 nm by the Pauli’s principle in the case of s-Si PWT. This theoretical value of Lmax should be compromised by considering actual PWT operation voltage for gate oxide breakdown.