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Abstract: In this study NPN rf power transistors were irradiated by 175 MeV Ni13+ ions in the dose range of 100 krad to 100 Mrad. Their characteristics such as excess base current (ΔI B = I Bpost − I Bpre), dc current gain (h FE), transconductance (g m) and collector-saturation current (I CSat) were studied before and after irradiation. The damage factor (K) for h FE was calculated using Messenger–Spratt relation. The base current (I B) was found to increase significantly after irradiation and in turn decreases the h FE. The g m and collector current (I C) in the saturation region (I CSat) were found to decrease with increase in radiation dose. The results obtained here were also compared with that obtained by 140 MeV Si10+ ions, 100 MeV F8+ ions, 95 MeV O7+ ions and 50 MeV Li3+ ions irradiation studies in the same dose ranges to understand the LET effects. The recovery in the I–V characteristics of irradiated NPN transistors were studied by isothermal and isochronal annealing methods. [Copyright &y& Elsevier]

Abstract: NPN RF power transistors were irradiated with 140MeV Si10+ ions, 100MeV F8+ ions, 50MeV Li3+ ions and Co-60 gamma radiation in the dose range from 100krad to 100Mrad. The transistor characteristics are studied before and after irradiation from which the parameters such as Gummel characteristics, excess base current (ΔI B = I Bpost − I Bpre), dc current gain (h FE), transconductance (g m) and collector-saturation current (I CSat) are determined. The degradation observed in the electrical characteristics is almost the same for different types of ion irradiated NPN RF power transistors with similar total doses although there is a large difference in the linear energy transfer (LET) of the ions. Further, it was observed more degradation in DC I–V characteristics of ion irradiated devices than the Co-60 gamma irradiated devices for higher doses. [Copyright &y& Elsevier]

Abstract: N-channel MOSFETs were irradiated by 48MeV Li3+ ions, 100MeV F8+ ions and Co-60 gamma radiation with doses ranging from 100krad to 100Mrad. The threshold voltage (V TH), voltage shift due to interface trapped charge (ΔV Nit), voltage shift due to oxide trapped charge (ΔV Not), density of interface trapped charge (ΔN it), density of oxide trapped charge (ΔN ot), transconductance (g m), mobility (μ) of electrons in the channel and drain saturation current (I D Sat) were studied as a function of dose. Considerable increase in ΔN it and ΔN ot, and decrease in V TH, g m and I D Sat were observed in all the irradiated devices. We correlated the degradation of μ with the ΔN it and the effect of ΔN ot is found to be negligible for degrading the μ. The maximum degradation was observed for the devices irradiated with Co-60 gamma radiation when compared with those irradiated with ions, since gamma radiation can generate more trapped charge in field oxide when compared to the high energy ions. [Copyright &y& Elsevier]

Abstract: N-channel depletion MOSFETs were irradiated with 140MeV Si10+ ions, 100MeV F8+ ions and 48MeV Li3+ ions in the dose range from 100krad to 100Mrad. The MOSFET parameters such as threshold voltage (V TH), transconductance (g m) and mobility of carriers (μ) were determined by systematically studying the I–V characteristics before and after irradiation. The ion irradiated results were compared with Co-60 gamma irradiated results in the same dose range. The degradation in V TH, g m and μ was found to be more for the devices irradiated with Co-60 gamma radiation than that irradiated with swift heavy ions. [Copyright &y& Elsevier]

Abstract: Third generation 200GHz silicon–germanium Heterojunction Bipolar Transistors (Si–Ge HBTs) were irradiated with high dose Co-60 gamma radiation up to 100Mrad. 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 100krad to 100Mrad of total doses. The Si–Ge HBTs showed robust ionizing radiation tolerance up to a total dose of 100Mrad. [ABSTRACT FROM AUTHOR]