Refractory SelfAlignedGate GaAs FET Based Circuit Technology for High Ambient Temperatures

Recent progress in the development of a hightemperature (300-400 °C) GaAs FET-based IC technology is reported. The development goal is a robust temperature-hard integrated circuit technology for data acquisition, processing, digitalcontrol and microwave rf applications. Our development approach retrofits an existing (1 ?>m) self-aligned-gate (SAG) MESFET process with temperature-hard ohmic contacts, a modified channel implant andgate sidewall spacers to allow FET operation and stability at temperatures to 400 °C. We report temperature stablity of the low contactresistance non-Au ohmic, a key for stable device operation. Electrical characteristics of 1.1 ?>m gate length FETs measured from 27- 400 °C after 400°C temperature stress arepresented; modeling the characteristics is discussed.