Insulator photocurrents: application to dose rate hardening of CMOS/SOI integrated circuits

Irradiation of insulators with a pulse of high energy x-rays can induce photocurrents in the interconnections of integrated circuits. We present, here, a new method to measure and analyse this effect together with a simple model. We also demonstrate that these insulator photocurrents have to be taken into account to obtain high levels of dose-rate hardness with CMOS on SOI integrated circuits, especially flip-flops or memory blocks of ASICs. We show that it explains some of the upsets observed in a SRAM embedded in an ASIC.