Reliability of GaAs MESFET Logic Circuits

Twelve depletion mode GaAs MESFET logic circuits were subjected to a step-stress life test. Each circuit consisted of an 11-stage ring oscillator with one buffer stage. Both BFL and SDFL circuits with Vp ¿ ¿2.0 V and ¿1.0 V were represented. The circuits were operated for 500 hours at each of eight temperature stress steps ranging between 25° and 200°C with 25°C increments. No chip failures occurred upon completion of the life test. Reasonable interpretation of these results suggests that GaAs MESFET logic circuits should be very reliable.