Terahertz Plasma Oscillations in Nanotransistors

Abstract

Scaling of the gate length of Field Effect Transistors (FET) down to nanometer size leads to THz plasma oscillations in the transistor channel. In this work we give an overview of our recent experimental results concerning this effect. The first observation of the resonant THz detection was demonstrated on 150 nm gate length GaAs FET. The most important recent result concerning the detection is a very strong (two orders of magnitude) enhancement of the photo-detection signal obtained by increasing of the drain current that drives the transistor towards the plasma instability. The first demonstration of THz plasma wave emission from a nano-transistor was observed on a 60nm InGaAs FET. The detailed mechanism of the emission is still under discussion. Some insight is given by Monte Carlo simulations, which show the importance of hot electron effects in the THz emission. The first results on room temperature THz detection in nanometer Si-MOSFETs were also demonstrated.