Terahertz plasma wave generation in ultra-short-channel Field Effect Transistors: theory vs experiment

TL;DR

This paper investigates the generation of terahertz plasma waves in ultra-short-channel FETs by analyzing the effects of scattering and velocity saturation, providing a theoretical framework aligned with experimental observations.

Contribution

It introduces a comprehensive theoretical model accounting for scattering and velocity saturation effects in plasma wave instability in FETs, and compares predictions with recent experimental data.

Findings

Scattering and velocity saturation damp plasma wave instability.

Threshold conditions for plasma wave generation are established.

Comparison with experiments confirms the model's relevance.

Abstract

Taking into account both the scattering and the velocity saturation of carriers, we examine the "shallow-water" instability of the two-dimensional electron gas in a field effect transistor. It is shown that both the scattering (which is analogous to friction in a shallow-water channel) and the carrier velocity saturation lead to damping of the plasma wave instability. Threshold diagram of instability is calculated. The actual device parameters required for observation of plasma wave generation are compared with those reported in recent sub-terahertz emission experiments.