BALLISTIC TRANSPORT AND HOT ELECTRON SPECTROSCOPY IN TUNNELLING HOT ELECTRON TRANSFER AMPLIFIER (THETA).

Abstract

An unambiguous demonstration of ballistic (collisionless) electron transport in GaAs with the aid of a THETA device is reported. As the base width was reduced to less than about 500 angstrom, quantum size effects began to be noticeable. Quasi-two-dimensional subbands were then formed in the based, influencing the injected tunneling current. The resultant transmission coefficient through the device was thus modulated with peaks that indicate the position of the subbands. A self-consistent calculation of the potential distribution in the base (satisfying Poisson and Schroedinger equations simultaneously) was needed to explain the position of the peaks.