Gallium Arsenide as a Competitor to Silicon for High-speed Amplification and Switching

A review is given of the physical and technological factors which affect the electrical behaviour of field-effect devices for high-speed applications. Ballistic electron transport is shown to lead to an electron transit time under the gate electrode which is shorter in GaAs than in Si field-effect transistors (FETs), providing a possible basis for exploitation of transport effects in high-speed devices. Some electrical characteristics of practical Si and GaAs field-effect structures are presented.