Effect of multiple-transistor charge collection on SET pulse widths

New heavy-ion data from a 130 nm bulk CMOS process shows a counterproductive result in using a common single-event charge collection mitigation technique. Guard bands can reduce single-event pulse widths for normal strikes, but increase them for angled strikes. Calibrated 3D TCAD mixed-mode modeling has identified a multiple-transistor charge collection mechanism that explains the experimental data, namely that angled strikes result in charge collection in the normally ON device that increases the restoring current on the struck device.