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The effects of high total dose proton irradiation on the reliability of silicon NPN rf power bipolar junction transistor (BJT) were examined by subjecting to 1, 3, and 5 MeV protons in the dose range from 100 Krad to 100 Mrad. The electrical characteristics such as Gummel characteristics (IB, IC-VBE), excess base current (ΔIB = IBpost – IBpre), current gain (hFE), and output characteristics (IC-VCE), built-in potential (Vbi) and the effective doping concentration (Nd) were studied before and after irradiation. SRIM simulation was conducted to understand the range and energy loss of protons in the BJT structure. SRIM and experimental results infer that the proton irradiation at lower energy (1 MeV) was found to degrade the current–voltage(I-V) and capacitance–voltage (C-V) characteristics more severely than higher-energy (3 and 5 MeV) proton irradiation. Thermal annealing on irradiated devices was also conducted to study the parametric recovery of irradiated devices. [ABSTRACT FROM AUTHOR]

The pre- and post-irradiation effects on the DC electrical characteristics of 100 MeV Phosphorous (P7+) and 80 MeV Nitrogen (N6+) ion-irradiated NPN transistors were studied in the dose range from 600 krad (Si) to 100 Mrad (Si). The different electrical characteristics, such as Gummel characteristics, excess base current (ΔIB = IB-Post – IB-Pre), current gain (hFE), damage constant (K) and output characteristics, were measured in situ after ion irradiation. The considerable increase in the base current (IB) at lower VBE and slight decrease in the collector current (IC) at higher VBE were observed after ion irradiation. The C–V measurements revealed that the doping concentration (Nd) was found decreased, while the built-in potential (Vbi) increased after irradiation. The ion-irradiated results are compared with 60Co gamma-irradiated results in the same dose range. The SRIM simulation was performed to understand the range of ions and energy loss in the transistor structure. The SRIM simulation showed that 100 MeV P7+ and 80 MeV N6+ ions can easily pass through the active region of transistors by creating ionization and displacement damages in the device structure. The irradiation results showed that ions induce more degradation in the electrical characteristics when compared to 60Co gamma radiation at the same dose range. [ABSTRACT FROM AUTHOR]

The total dose effects of 5 MeV proton and Co-60 gamma irradiation in the dose range from 1 to 100 Mrad on advanced 200 GHz Silicon–Germanium heterojunction bipolar transistors (SiGe HBTs) are investigated. The SRIM simulation study was conducted to understand the energy loss of 5 MeV proton ions in SiGe HBT structure. Pre- and post-radiation DC figure of merits such as forward- and inverse-mode Gummel characteristics, excess base current, DC current gain and output characteristics were used to quantify the radiation tolerance of the devices. The results show that the proton creates a significant amount of damages in the surface and bulk of the transistor when compared with gamma irradiation. The SiGe HBTs shows robust ionizing radiation tolerance even up to a total dose of 100 Mrad for both radiations. [ABSTRACT FROM PUBLISHER]