Electron Beam Simulation of Pulsed Photon Effects in Electronic Devices at Very High Doses and Dose Rates

Large high-energy flash X-ray simulation facilities are expensive to build and operate. As a result, the radiation effects community has at it's disposal a limited number of X-ray sources with the capability of providing the very high levels of radiation (hundreds of k rad(Si)) required for R and D. Because of the inefficiency of bremsstrahlung production, an accelerator which provides only small doses in the X-ray mode could readily provide the very high total doses and associated dose rates via direct electron irradiation. A prerequisite for electron beam testing is a satisfactory demonstration of the fidelity of the simulation. This paper presents the experimental details and results of such an assessment. It was demonstrated in this work that electron beams do simulate the effects of high-energy bremsstrahlung X-rays when testing semiconductor devices for very high dose and dose rate effects. However, it was also found that the effects of charge deposition from the electron beam can dramatically perturb the nominal irradiation bias conditions. In electronic devices where radiation induced degradation is a function of applied potentials (e.g., MOS devices), this charge capture can totally invalidate the simulation unless the experimenter is aware of and compensates for the effect.