Oblique modes effect on terahertz plasma wave resonant detection in InGaAs∕InAlAs multichannel transistors

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

“…The typical schematic view of a high electron mobility transistor structure www.intechopen.com plasma wave resonant detection at low temperature in 200 nm gate length InGaAs/InAlAs multichannel HEMT. To achieve selective resonant and voltage tunable terahertz emission, they have maintained the gate width is in the order of the gate length [Shchepetov et al, 2008].The typical schematic of a High electron mobility transistor used for THz detection is shown in fig.3.…”

Field effect transistors for terahertz detection - silicon versus III–V material issue

“…Two main hypotheses on the origin of an additional broadening are currently under consideration: l existence of oblique plasma modes [19,20], l additional damping due to the leakage of gated plasmons to ungated parts of the transistor channel [21]. The first hypothesis is related to the fact that in realistic devices the gate width is much greater than the gate length.…”

“…Therefore, the plasma under the gate cannot be treated independently of the plasma in ungated parts. An interaction between the two plasma regions can lead not only to a modification of the resonant frequency [19,21], but also to line broadening. To decrease the role of oblique modes, one has to change the geometry of the channel.…”

Viscous hydrodynamic model of non-linear plasma oscillations in two-dimensional gated conduction channels and application to the detection of terahertz signals

“…The boundary conditions are U(0,t) = U 0 + U a cos(ωt) at the source side of the channel and zero current at the drain side, j(L,t) = 0. In the detector mode, the time-harmonic part is induced by the external radiation (1)(2)(3)(4)(5)(6)(7). Here the analysis is restricted to a one-dimensional flow that is uniform in the transverse channel direction:…”

“…In the Dyakonov-Shur detector, a short channel HEMT is used for the resonant tunable detection of terahertz radiation. The non-linear plasma response has been observed in InGaAs (3,4) and GaN (5-8) HEMTs, in the frequency range from 0.2 to 2.5 THz. The emission of radiation is also possible due to amplification of plasma oscillations upon reflection of plasma waves at the channel lateral boundaries, which has been shown to lead to plasma instability under certain boundary conditions (9).…”