Articles you may be interested inNoise and terahertz rectification linked by geometry in planar asymmetric nanodiodes Appl. Phys. Lett. 94, 093512 (2009); 10.1063/1.3095845Terahertz Gunn-like oscillations in InGaAs/InAlAs planar diodes

By using a semi-classical two-dimensional Monte Carlo simulation, simple devices (T-branch junctions (TBJs) and rectifying diodes) based on AlInAs/InGaAs ballistic channels are analysed. Initially, the model is validated by means of Hall-effect measurements of mobility and electron concentration in long (diffusive) channels. Then, quasi-ballistic transport at room temperature is confirmed in a 100 nm channel. Our simulations qualitatively reproduce the experimental results of electric potential measured in a TBJ appearing as a result of electron ballistic transport, and in close relation with the presence of space charge inside the structure. As examples of devices exploiting the ballistic transport of electrons, preliminary simulations of a multiplexor/demultiplexor and a rectifying diode are presented, demonstrating their capability for terahertz operation.

By using a semi-classical two-dimensional (2-D) Monte Carlo simulation, simple ballistic devices based on AlInAs/InGaAs channels are analyzed. Our simulations qualitatively reproduce the experimental results in T-and Y-branch junctions as well as in a ballistic rectifier appearing as a result of electron ballistic transport. We show that a quantum description of electron transport is not essential for the physical explanation of these results since phase coherence plays no significant role. On the contrary, its origin can be purely classical: the presence of classical electron transport and space charge inside the structures.

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The static and dynamic behavior of InAlAs/InGaAs double-gate high-electron mobility transistors (DG-HEMTs) is studied by means of an ensemble 2-D Monte Carlo simulator. The model allows us to satisfactorily reproduce the experimental performance of this novel device and to go deeply into its physical behavior. A complete comparison between DG and similar standard HEMTs has been performed, and devices with different gate lengths have been analyzed in order to check the attenuation of short-channel effects expected in the DG-structures. We have confirmed that, for very small gate lengths, short-channel effects are less significant in the DG-HEMTs, leading to a better intrinsic dynamic performance. Moreover, the higher values of the transconductance over drain conductance ratio g m /g d and, especially, the lower gate resistance R g also provide a significant improvement of the extrinsic f max. Index Terms-Double-gate high-electron mobility transistor (DG-HEMT), dynamic behavior, Monte Carlo (MC) simulations.