Technologies for High-Speed Compound Semiconductor ICs

Abstract

The development of process technologies for high-speed integrated circuits in compound semiconductor materials presents a number of wide-ranging challenges for the process engineer. For analog applications the diversity of frequencies from about 1 GHz to 100 GHz means that a standard technology cannot be adopted for the whole frequency spectrum as the circuit topologies required at each end of this frequency range differ widely. At low frequencies, ∼1 GHz, traditional distributed (microstrip) style matching elements consume too much surface area of GaAs and so rf techniques using lumped inductors, capacitors, and resistors are used. It is only at frequencies in excess of 6–7 GHz that fully distributed circuits are small enough to enable utilization of this type of impedance matching. In digital circuits the challenge is in yield improvement, the close spacing of components and signal lines, and the level of integration.