Reliability of passivated 0.15 mu m InAlAs/InGaAs HEMT's with pseudomorphic channel

Accelerated life tests of 0. 15 mu m gate length InAlAs/InGaAs HEMTs were performed under DC electrical stress at four temperatures in nitrogen. By defining a 100 per cent-degradation of transconductance as failure criterion we found an activation energy of 1.8 eV and a projected life time of 5x10(exp 6) h at 125 degree ambient temperature. The degradation was found to be much faster in air than in nitrogen. High temperature storage tests showed that our devices are not sensitive to hydrogen.