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

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(MOSFET) is on strong inversion which is believed to be an operation regime of PWT THz emitter, Boltzmann statistics is no longer valid and degenerate Fermi-Dirac distribution should be considered.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 (L-max) to 17 nm for strained silicon (s-Si) PWT with assuming mu = 500 cm(2).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 L-max for enhanced mu is limited to near 35 nm by the Pauli's principle in the case of s-Si PWT. This theoretical value of L-max should be compromised by considering actual PWT operation voltage for gate oxide breakdown. (C) 2015 The Japan Society of Applied Physics