Gamma Radiation Effects on Different Varieties of SiGe:C HBT Technologies

We have studied the ionization damage produced by gamma irradiation on transistors from three different varieties of SiGe:C HBT technologies from Innovation for High Performance Microelectronics (IHP), Germany. The results show strong gain degradations at the highest doses, with an indication of damage saturation. We did not observe strong differences in radiation tolerance among the three different technologies. These studies are in the framework of the radiation assurance tests of SiGe BiCMOS technologies for their possible application in the front-end readout electronics of the detector modules of the future ATLAS upgrade for the Super-LHC, but space-oriented applications are also considered. A comparison is presented with previous gamma irradiations of different SiGe technologies in the literature.