Application of advanced 200 GHz Si–Ge HBTs for high dose radiation environments

Third generation 200 GHz silicon–germanium Heterojunction Bipolar Transistors (Si–Ge HBTs) were irradiated with high dose Co-60 gamma radiation up to 100 Mrad. Pre-radiation and post-radiation DC figures of merits were used to quantify the radiation tolerance of the different geometry devices. The different electrical characteristics like Gummel measurements, excess base current, current gain, transconductance, neutral base recombination, avalanche multiplication of carriers and output characteristics were studied for different doses from 100 krad to 100 Mrad of total doses. The Si–Ge HBTs showed robust ionizing radiation tolerance up to a total dose of 100 Mrad.