Study of single-event phenomena on recent semiconductor devices. Development of a new measuring method

For practical use of semiconductor devices and integrator circuits in the cosmic environment, it is most important to take measures for the single-event-upset phenomena induced by heavy ion incidence. Transient currents of pico-second in a pn junction diode induced by heavy ion incidence are measured for investigation of single-event-upset mechanism. Transient-ion beam induced charge collection (TIBIC) system which consists of single-event transient current measuring system and a fast beam switch installed in heavy ion beam line is developed for reducing radiation damage of the pn junction diode resulting from heavy ion incidence. The TIBIC system is able to observe a wave form of single-event transient current, as well as an image for location of heavy ion incidence. Silicon and gallium arsenic diodes with sensitive area of 50 μ m φ are irradiated by 15 MeV carbon ion of 1 μ m width. Transient current wave forms of single event at the centre and edge region of the diode are measured. Images produced from the transient current data are taken by a photograph. The TIBIC system is expected to be able to observe directly the charge behaviors of single-event phenomena in semiconductor diode generated by a single ion incidence, and to reduce radiation damage of the diode. (M. Suetake)