Lifetime acceleration model for HAST tests of a pHEMT process

Abstract We report the results of DC biased life tests performed on gallium arsenide pseudomorphic high electron mobility transistor (GaAs pHEMT) switches under elevated temperature and humidity conditions. The goal of this work was to determine whether the acceleration factors typically reported for silicon technologies are also appropriate for GaAs technologies. Toward that end we performed tests at three different temperatures and two different humidity conditions. Failure distributions were generated for each life test, and the results applied to an acceleration model commonly used for HAST. We determined the activation energy for the failures observed during these tests to be 0.81 eV; similar to values commonly reported for HAST tests of silicon technologies. In contrast, our results show significantly stronger stress acceleration due to relative humidity (RH−10.7) than is typically reported for silicon (RH−3.0). Examples of typical visual and electrical device failure signatures are shown.