OPERATION OF A BALLISTIC HETEROJUNCTION PERMEABLE BASE TRANSISTOR

A ballistic heterojunction permeable base transistor (HPBT) is propose d and an analytical and numerical analysis of the device is performed. The new feature of the device structure is an AlGaAs hetero-emitter f or injection of hot electrons into a 150-nm-thick GaAs base layer. A t ungsten grating is embedded in the base layer and the Schottky depleti on around the metal wires controls the vertical current. In this inves tigation, it is established that the high velocity of the hot electron s will prevent charge accumulation in the base layer. Thereby the depe ndence of the doping on the transconductance is lower than for the per meable base transistor. The HPBT is expected to have a unity-current g ain cut-off frequency above 300 GHz.