Solid state: Integrated circuits: The case for gallium arsenide: This superfast semiconductor holds great promise for high-speed computers, and manufacturing difficulties are now beginning to be overcome

Because of its energy-band structure, gallium arsenide is an ideal medium for achieving blinding speed in electronic devices and circuits. Electrons in GaAs are exceedingly “light“ and highly mobile; the effective mass of its electrons is only 7 percent that of electrons in silicon, and electron mobility in the channels of GaAs field-effect transistors (FETs) is about an order of magnitude higher than in silicon FETs. Electron velocities measured in GaAs transistor structures range up to 5 × 107 meters per second - about five times those achieved in silicon devices. Furthermore, GaAs is readily available in a semi-insulating substrate form that substantially reduces parasitic capacitances, so its outstanding device speeds can be fully realized in integrated circuits.