The physics of the two-dimensional electron gas base vertical hot electron transistor

The authors describe a vertical hot electron transistor structure in the GaAs/AlGaAs materials system, in which the base is a two-dimensional electron gas in GaAs. They undertake initial studies of the hot electron spectroscopy at low temperature, and corroborate the high common base current gain measured to be >100 at low temperature, the best result ever achieved for a unipolar transistor. They compare these attractive results with the less satisfactory results achieved earlier with a uniformly doped (3D) GaAs base. A number of devices have been made which allow magnetotransport and Hall measurements to be performed on the base while the transistor is operating.