80 MeV carbon ion irradiation effects on advanced 200 ghz silicon-germanium heterojunction bipolar transitors

The total dose effects of 80 MeV carbon ions and 60Co gamma radiation in the dose range from 1 Mrad to 100 Mrad on advanced 200 GHz Silicon-Germanium heterojunction bipolar transistors (SiGe HBTs) are investigated. The stopping and range of ions in matter (SRIM) simulation study was conducted to understand the energy loss of 80 MeV carbon ions in SiGe HBT structure.Pre- and post-radiation DC figure of merits such as Gummel characteristics, excess base current, ideality factor, DC current gain, damage constant, neutral base recombination, avalanche multiplication of carriers and output characteristics were used to quantify the radiation tolerance of the devices. The excess base current, current gain and damage constant for 80 MeV carbon irradiated SiGe HBTs show more degradation when compared to 60Co gamma irradiation. The ideality factor for 80 MeV carbon ions irradiated SiGe HBTs is also more when compared to 60Co gamma irradiated SiGe HBTs. The SiGe HBTs shows minimal degradation in current gain at collector current levels (~ 1 mA) where the circuits are biased even after 100 Mrad of total dose. Therefore SiGe HBTs are became the reliable candidate for deep space exploration programs and high energy physics experiments (HEP) like large hadron colliders (LHCs)