A novel GaAs Schottky-drain power FET for microwave application

A GaAs Schottky-drain power FET (SDFET) having a 2.4-mm gate periphery and 1.5-micron gate length has been developed, and is shown to realize excellent performance at 10 GHz. An output power in excess of 1 W, and a 36-percent power-added efficiency (PAE) are demonstrated. These devices were fabricated on epitaxial layers grown on 2-micron-thick buffer layers using vapor-phase epitaxy. With the exception of the mesa and recess channels, which were defined by conventional chemical etch, the devices were processed by the plasma dry-etch technique. For the Schottky junctions and source ohmic contacts, tantalum with a thick gold overlayer and GeAu, were used, respectively.