Plasma oscillations in high-electron-mobility transistors with recessed gate

Abstract

We calculate the plasma oscillation spectrum in high-electron-mobility transistors (HEMTs) with recessed gate having the highly doped caps adjacent to the source and drain contacts and the windows between the caps and the gate. The resonant plasma frequencies are found as functions of the lengths of the gate, cap, and window regions, the electron concentration in the transistor channel, and the gate voltage. We demonstrate that the effect of cap region can result in a significant reduction of the resonant frequencies in comparison with those calculated for simplified HEMT model. This can provide a plausible explanation of the data obtained in recent experimental studies of the detection of terahertz radiation in and its emission from HEMTs.

Terahertz Resonant Detection by Plasma Waves in Nanometric Transistors

“…The transistor consists not only of the gated part but also of the ungated part that is covered by the cap layer. As predicted in [13], the cap regions significantly affect the plasma oscillation spectrum in HEMTs: the resonant plasma frequencies dramatically decrease with increasing cap region length. In order to take into account the effect of such cap layers, a correction to Eq.…”

Resonant plasmonic terahertz detection in vertical graphene-base hot-electron transistors

“…Σ 0 being the so-called "fictituous" effective hole (electron) mass in graphene layers [27], ν = (σ B,ω /W E C g ) and ν = 1/τ +ν, where τ is the hole momentum relaxation time in the 2DHG andν =ν visc +ν rad is associated with the contribution of the 2DHG viscosity to the damping (see for example, Ref. [21]) and with the radiation damping of the plasma oscillations.…”

“…The detector responsivity R ω ∝ δJ C,ω /|δV ω | 2 . Due to the possibility of the plasmonic resonances, the rectified component (the detector output signal) can be resonantly large, similar to that in the HET detector [21] and other plasmonic THz detectors using different transistor structures, including those incorporating graphene [22][23][24][25][26][27][28][29][30][31][32][33][34].…”

Terahertz Emitters, Detectors and Sensors: Current Status and Future Prospects

“…The antenna, placed at the focal point of the parabolic mirror, quasioptically collects the terahertz signalleading to superior performance. Ryzhii et al, [Ryzhii et al, 2006] investigated the plasma oscillations in a two-dimensional electron channel with a reverse-biased Schottky junction. They show that the plasma instability can be used in a novel diode device -lateral Schottky junction tunneling transit-time terahertz oscillator.…”

“…They have showed that these transistors are tunable by the gate voltage between 0.75 and 2.1 THz. It is also possible to tune operating frequency by manipulating cap, window, and gate lengths and other structural parameters [Ryzhii et al, 2006].…”