a High-Gain InAs Thin-Film Transistor

InAs thin films have been prepared by coevaporation. Hall mobilities up to 8000 cm²/V-sec have been obtained in films 3000-Å thick, and 3000 cm²/V-sec in 1000-Å films. Field-effect transistors have been fabriacted of such films, exhibiting good saturation in both enhancement and depletion modes of operation. Field-effect mobilities of 1800 cm²/V-sec, transconductances of 10,000 μ-mhos and gain-bandwidth products of 8 MHz were obtained in devices with a 100-μ source-drain spacing. Performance in the GHz region is predicted for devices of suitable geometry.