IMPROVED HETEROJUNCTION BIPOLAR-TRANSISTOR RELIABILITY WITH CARBON-DOPED BASE

AlGaAs/GaAs heterojunction bipolar transistors (HBTs) with the carbon- or beryllium-doped base have been fabricated and characterized with r espect to device reliability. Under high current stress at elevated te mperature, the device characteristics of the HBT with the beryllium-do ped base show severe degradation enhanced by ion implantation. In comp arison, the HBT with the carbon-doped base is not affected by the ion implantation and exhibits negligible device degradation after the stre ss. These results indicate the advantage of carbon doping for better H BT reliability. (C) 1996 American Institute of Physics.