Testing Radiation damage in III-V Transistors

HBTs, MESFETs, and pHEMTs were measured on- wafer before and after irradiation by 3MeV protons at a dose of 10 13 cm -2 . The HBT current gains decreased because the collector currents decreased and the base currents increased. This was modeled using G-PISCES-2B assuming that the radiation reduced the recombination lifetimes in the base by about a factor of 0.05. The model is partially verified by periphery-to-area dependencies. The FET and HEMT pinchoff voltages Vp increased by 6 to 19% of the depletion voltage (Vbi-Vp, where Vbi~0.78V) and are modeled assuming 0.6 to 1.2x10 16 cm -3 deep-donor