High energy swift heavy ion irradiation and annealing effects on DC electrical characteristics of 200 GHz SiGe HBTs

Abstract

The total ionizing dose (TID) and non ionizing energy loss (NIEL) effects of 100 MeV phosphorous (P7+) and 80 MeV nitrogen (N6+) ions on 200 GHz silicon-germanium heterojunction bipolar transistors (SiGe HBTs) were examined in the total dose range from 1 to 100 Mrad(Si). The in-situ I–V characteristics like Gummel characteristics, excess base current (ΔIB), net oxide trapped charge (NOX), current gain (hFE), avalanche multiplication (M − 1), neutral base recombination (NBR) and output characteristics (IC-VCE) were analysed before and after irradiation. The significant degradation in device parameters was observed after 100 MeV P7+ and 80 MeV N6+ ion irradiation. The 100 MeV P7+ ions create more damage in the SiGe HBT structure and in turn degrade the electrical characteristics of SiGe HBTs more when compared to 80 MeV N6+. The SiGe HBTs irradiated up to 100 Mrad of total dose were annealed from 50 °C to 400 °C in different steps for 30 min duration in order to study the recovery of electrical characteristics. The recovery factors (RFs) are employed to analyse the contribution of room temperature and isochronal annealing in total recovery. Keywords: SiGe HBT, Ion irradiation, Gamma irradiation, Current gain degradation, Isochronal annealing, Recovery factors