FAILURE MECHANISMS IN ALGAAS GAAS HEMTS

Failure mechanisms in AlGaAs/GaAs high electron mobility transistors ( HEMTs) life tested under high temperature storage, high temperature wi th d.c. bias, and high temperature with d.c. bias under r.f. drive hav e been determined to differ significantly. Monte Carlo modeling has be en used to explain the experimental data, which shows evidence of gate sinking, ohmic contact degradation, and trapped charge formation near the two-dimensional gas (2DEG). Of particular interest is the evidenc e of damage from hot carriers under the stress conditions of high temp erature with d.c. bias under r.f. drive, which most closely simulates actual use conditions.