Comparison between the dynamic performance of double-and single-gate AlInAs/InGaAs HEMTs

Abstract

Se han estudiado las características estáticas y dinámicas de HEMTs de doblre puerta (DG-HEMTs) por medio de simulaciones Monte Carlo, y se han comparado con las de los HEMTs de puerta única. Las simulaciones reproducen adecuadamente los resultados experimentales y permiten confirmar y explicar desde el punto de vista microscópico el origen de la reducción de los efectos de canal corto y el aumento de fmax que se observa en los transistores de doble puerta.

The static and dynamic behavior of InAlAs/InGaAsdouble-gate high-electron mobility transistors (DG-HEMTs) isstudied by means of an ensemble 2-D Monte Carlo simulator.The model allows us to satisfactorily reproduce the experimentalperformance of this novel device and to go deeply into its physicalbehavior. A complete comparison between DG and similarstandard HEMTs has been performed, and devices with differentgate lengths have been analyzed in order to check the attenuationof short-channel effects expected in the DG-structures. Wehave confirmed that, for very small gate lengths, short-channeleffects are less significant in the DG-HEMTs, leading to a betterintrinsic dynamic performance. Moreover, the higher values ofthe transconductance over drain conductance ratio gm/gd and,especially, the lower gate resistance Rg also provide a significantimprovement of the extrinsic fmax.