Bipolar junction test structures packaged in hermetically sealed packages with excess molecular hydrogen (H₂) showed enhanced degradation after radiation exposure. Using chemical kinetics, we propose a model that quantitatively establishes the relationship between excess H₂ and radiation-induced interface trap formation. Using environments with different molecular hydrogen concentrations, radiation experiments were performed and the experimental data showed excellent agreement with the proposed model. The results, both experimentally and theoretically, showed increased radiation induced degradation with H₂ concentration, and device degradation saturate at both high and low ends of H₂ concentrations.

It is experimentally demonstrated with test transistors and circuits that hydrogen is correlated with enhanced low dose rate sensitivity (ELDRS) in bipolar linear circuits. These experiments show that the amount of hydrogen determines the total dose response versus dose rate, both the saturation at low dose rate and the transition dose rate between the high and low dose rate responses. The experimental results are supported with modeling calculations using REOS (radiation effects in oxides and semiconductors).

This paper evaluates the radiation responses of 2.5 V I/O transistors and regular-threshold MOSFETs from a 90 nm commercial bulk CMOS technology. The data obtained from Co ionizing radiation experiments indicate enhanced TID susceptibility in I/O devices and circuits, which is attributed to the p-type body doping. A quantitative model is used to analyze the effects of doping and oxide trapped charge buildup along the sidewall of the shallow trench isolation oxide. These effects are captured in the general electrostatic equation for surface potential, which can be correlated to off-state leakage current. Device simulations are used in concert with experimental measurements and the analytical model to provide physical insight into the radiation response of each device type.

Engineering education by its nature is a costly program in university environments. Perhaps the most costly component is the laboratory facility, usually consisting of specialized equipment. Effective instruction of some topics in power engineering education requires experience with actual equipment, rather than small-scale replicas or simulation. In this paper, a new laboratory approach is described, as implemented in a virtual, Internet-based, experimentation platform. This virtual laboratory (VLab) utilizes real equipment distributed among multiple universities from which remotely located students can perform experiments. The software solution is a multiuser, client-server architecture developed in the LabVIEW environment. Implementation details including video, chat, archiving, and the hardware and software platforms are presented in the paper. An example presented herein is the study of current and voltage waveforms while controlling relays and low-voltage contactors. The applications have been tested with student teams enrolled in the electrical engineering department of Politehnica University of Bucharest and the power engineering program at Arizona State University.

The total ionizing dose (TID) effect of gamma-ray (γ-ray) irradiation on HfOx based resistive random access memory was investigated by electrical and material characterizations. The memory states can sustain TID level ∼5.2 Mrad (HfO₂) without significant change in the functionality or the switching characteristics under pulse cycling. However, the stability of the filament is weakened after irradiation as memory states are more vulnerable to flipping under the electrical stress. X-ray photoelectron spectroscopy was performed to ascertain the physical mechanism of the stability degradation, which is attributed to the Hf-O bond breaking by the high-energy γ-ray exposure.